Definition of cluster in English:



  • 1A group of similar things or people positioned or occurring closely together.

    ‘clusters of creamy-white flowers’
    ‘they stood there in a frightened cluster’
    • ‘Javion picked a beautiful purple flower from a small cluster of flowers, and offered it to me.’
    • ‘‘For novices, I would say that the easiest way to form the wreath is by simply poking the clusters of greenery into the bound hay, newspaper or moss,’ says Elaine.’
    • ‘It is these adult shoots that produce the flowers and berries - clusters of tiny, nectar rich blossoms, followed by round, blue-black, yellow or orange fruits.’
    • ‘This deciduous upright, open shrub has glossy, bright green leaves and short clusters of fragrant, clove-scented golden yellow flowers from mid spring onwards.’
    • ‘This shrub bears clusters of white flowers in the spring.’
    • ‘White lights entwined with silver ribbon draped the window sills, door frames, and banister, bunched with clusters of holly and mistletoe.’
    • ‘They are very hardy and produce large clusters of small flowers.’
    • ‘Small flowers in large, dense clusters are produced only in spring.’
    • ‘The deer continues moving past the cluster of grapevines I'm hiding in and now I can see her clearly.’
    • ‘Whole bunches or clusters of grapes are deliberately placed, with care to ensure that the berries are not broken, in an anaerobic atmosphere, generally obtained by using carbon dioxide to exclude oxygen.’
    • ‘The flowers are borne in large clusters of 15 to 24 units, with each unit maturing at different times although flowering during the same season.’
    • ‘Berries start off green, closely resembling a small gooseberry, and hang firmly in clusters of three to five.’
    • ‘Blooms appeared in long clusters of densely packed white flowers.’
    • ‘The nashi grow in tight clusters of 8-10 fruits, and each cluster needs to be carefully dismantled and the fruits clipped off one at a time, then carefully packed.’
    • ‘She rushed over to his cluster of trees, gripping one as she lurched forward, racing with her eyes to see what was the source.’
    • ‘Many environmental factors may stimulate cluster root formation.’
    • ‘At the top of the stems there are tightly packed bracts of rich blues and purples surrounding clusters of purple-blue flowers in late spring and summer.’
    • ‘Botrytis bunch rot is especially severe in grape cultivars with tight, closely packed clusters of fruit.’
    • ‘Two of the squad, perhaps more accustomed to the city environment than jogging about in the sticks, got a little freaked out by the clusters of trees, and were separated from the main party.’
    bunch, clump, collection, mass, knot, group, clutch, bundle, nest
    crowd, group, knot, huddle, bunch, gathering, throng, swarm, flock, pack, troupe, party, band, body, collection, assemblage, congregation
    View synonyms
    1. 1.1Astronomy A group of stars or galaxies forming a relatively close association.
      ‘there are several clusters in Cassiopeia’
      • ‘We know what matter looks like today because we see galaxies, galaxy clusters, and galaxy superclusters.’
      • ‘We sometimes use the word nebula to refer to galaxies, various types of star clusters, and various kinds of interstellar dust or gas clouds.’
      • ‘There exists a well-defined population of material aggregates in the Universe - planets, stars, galaxies, and clusters.’
      • ‘By the end of that process, matter could move and coalesce on its own, forming planets and stars, as well as galaxies, clusters, and superclusters.’
      • ‘There is a higher proportion of elliptical and fast-rotating spiral galaxies in dense clusters than in small groups.’
      • ‘A team of European astronomers, including several from the UK, have uncovered a super star cluster in our own Galaxy, the Milky Way.’
      • ‘Caroline also compiled catalogs of star clusters and nebulae.’
      • ‘Galaxies often congregate to form clusters of galaxies.’
      • ‘The centre of our galaxy lies within a cluster of stars in the constellation Sagittarius.’
      • ‘Among the many mysteries in the universe is the dark matter in galaxies and clusters.’
      • ‘An excellent example is the cosmological problem, since it contains scales of interest ranging from that of a single star to that of a large cluster of galaxies.’
      • ‘Astronomical observations have confirmed more or less beyond doubt that stars, galaxies and clusters of super galaxies are receding from the earth and from one another.’
      • ‘The most easily visible part of galaxy clusters, i.e. the stars in all the galaxies, make up only a small fraction of the total of what makes up the cluster.’
      • ‘These large dark clouds may eventually evaporate or, if there are sufficiently dense condensations within them, give birth to small star clusters.’
      • ‘They're searching for superdistant, ancient protogalaxies lurking behind huge clusters of galaxies closer to Earth.’
      • ‘Astronomers may see meteors produced by the annual Perseid shower, before pointing their telescopes at distant galaxies and star clusters.’
      • ‘Astronomers have long exploited this correlation between age and color to study the ages of stellar populations in star clusters and galaxies.’
      • ‘A double star cluster in a satellite galaxy of the Milky Way is pictured above.’
      • ‘Two vast cavities extend away from the super massive black hole in the cluster's central galaxy.’
      • ‘Studies of two distant galaxy clusters have found that galaxies formed relatively early in the history of the Universe.’
    2. 1.2Linguistics A group of consonants pronounced in immediate succession, as str in strong.
      • ‘This paper examines one aspect of second language syllable structure, syllable-final clusters, in the English of a Vietnamese L1 speaker.’
      • ‘The software was unaware of complex character clusters associated with consonant/vowel modifiers in Indian languages.’
      • ‘I believe that the programme allows up to 9 consonants in a cluster, but only word-internally.’
      • ‘The present orthographic system was introduced in the fourteenth century by the religious reformer Jan Hus, who instituted a system of diacritical markings to eliminate consonant clusters.’
      • ‘Thus, our strong emphasis on onset clusters succeeded in inducing a small but reliable transfer effect.’
      • ‘… if one chooses the Latin, French, or Italian language, since German is much more difficult because of its many closed syllables and consonant clusters.’
      • ‘Let's say you're in a language that uses schwa to break up consonant clusters, but nowhere else.’
      • ‘Consonants regularly occur in strings or clusters without intervening vowels: initially, as in stain and strip, finally, as in fetch and twelfth, medially, as in dodging.’
    3. 1.3 A natural subgroup of a population, used for statistical sampling or analysis.
      ‘ten clusters from all the primary health centres were selected’
      • ‘As noted above, cluster sampling tends to underestimate the impact of focused violence.’
      • ‘Cluster analysis was used to determine the clustering of populations in multivariate space.’
      • ‘A major issue in any study is maintaining the distinction between statistical clusters and their geographical expression.’
      • ‘Using cluster analysis, a statistical method that determines subpopulations in a group, three distinct patterns of behavior emerged.’
      • ‘Policy makers should consider testing health service innovation using cluster randomised controlled trials with the hospital as the sampling unit.’
      • ‘A common approach is to initially treat every sample as a cluster and to join the closest clusters together.’
      • ‘Despite the small sample sizes for some of our cluster groups, many cluster differences still attained statistical significance.’
      • ‘We also recruited a large number of clusters and performed statistical analyses taking cluster randomisation into account.’
      • ‘These were considered sufficiently small to assume statistical independence within a cluster.’
      • ‘This difference was significant, even in the rigorous statistical analysis for the cluster level design, controlling for confounding variables.’
      • ‘The researcher used cluster sampling in this study and also eliminated participant duplication.’
      • ‘It says a long-term epidemiological study should be set up in the area to establish if there are any clusters of diseases which might be attributable to the radar's presence.’
      • ‘Moreover, except for this one attempt nobody has tried to use cluster sampling to measure deaths by violence.’
      • ‘The examples focus on the process of conducting a cluster analysis of transfer pricing.’
      • ‘However, an expert at the Institute of Occupational Medicine in Edinburgh said it was ‘probably true’ that most clusters of illness happened by chance.’
      • ‘To determine how many natural clusters exist within a given sample, various stopping rules have been developed.’
      • ‘However, use of cluster randomisation rapidly leads to a doubling of the sample size.’
      • ‘Each cluster should be a statistical scale-model of the entire population.’
      • ‘Cluster sampling is a sampling technique where the entire population is divided into groups, or clusters, and a random sample of these clusters is selected.’
      • ‘The critical thing to understand here is that statistics cannot tell you the likely deviation of a cluster sample unless the distribution is random!’
    4. 1.4Chemistry A group of atoms of the same element, typically a metal, bonded closely together in a molecule.
      ‘noble-metal clusters supported on an acidic carrier’
      as modifier ‘a cluster compound’
      • ‘In metallic clusters, the metal atoms are either directly bonded through metal-metal interactions or are bridged by appropriate ligands.’
      • ‘In the centers of these molecular clusters, called micelles, the molecular chains are packed together densely.’
      • ‘Research has since shown that laser vaporization of graphite produces clusters of carbon atoms whose sizes range from two to thousands of atoms.’
      • ‘Proteins containing iron-sulfur clusters play important roles in biological systems.’
      • ‘These cluster ions can, however, be broken up by a flow of dry nitrogen gas (curtain gas).’
      • ‘Nevertheless, there were no significantly supported clusters including molecules from both vertebrates and invertebrates.’
      • ‘Similar patterns are seen in small atomic systems, such as the closed shells of valence electrons in metal clusters.’
      • ‘These clusters were once separate molecules, called amino acids.’
      • ‘A chelate is a chemical compound in which one atom is enclosed within a larger cluster of atoms that surround it like an envelope.’
      • ‘Absorbing a photon can force a photosensitive cluster of atoms to reposition a chemical bond and create a kink in a polymer chain.’


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  • 1Form a cluster or clusters.

    ‘the children clustered round her skirts’
    • ‘The crowd clustered round the sandy square was yelling encouragement at the players, who frowned in concentration in the fading light.’
    • ‘I was in my car and heading out of the driveway yesterday when I noticed the pigeons clustered around outside the second story window of the barn.’
    • ‘Inevitably, most of the early morning shoppers clustered around the road, trying to get a look at what was going on.’
    • ‘The five of us spent the next few hours clustered around the pool table.’
    • ‘But they don't live alone, they cluster together in tight-knit communities and range out along the verges and in warm spots under hedges and at the edge of copses and thickets.’
    • ‘In a knowledge economy, smart people tend to cluster together.’
    • ‘Several other decisions were made within the first hour as journalists clustered round the newsroom television sets.’
    • ‘Teenagers clustered around in groups, chattering excitedly or busy text messaging family to pass on the news before rushing off to celebrate in the sun, although it was not all joy.’
    • ‘The cars of the migrants crawl west by day, and cluster together beside the roads by night.’
    • ‘Guests, many with sons and daughters in the U.S., clustered round the TV.’
    • ‘Five kids cluster around her, asking her to fill in the yellow certificate showing they've put in their time.’
    • ‘Inside the home, the girl and her brothers clustered around the mother.’
    • ‘Most people cluster on the peaks of mountains and build their houses on stilts, hoping to keep their youth as long as possible.’
    • ‘A bunch of small children had clustered around it - it was the only one on the street.’
    • ‘We got back to find a huge crowd of people clustered around his desk whispering and giggling.’
    • ‘Defensive, impenetrable, they cluster together for security, and perhaps that is part of the artist's intention.’
    • ‘We clustered around the few desks with radios; some went back to their desks, tried to work, tried to bring up the Internet, and returned to the radio.’
    • ‘Other young women in headscarves clustered around her, their eyes blazing too.’
    • ‘Fire trucks clustered around the scene and the ground was covered with mounds of white, fire-retardant foam.’
    • ‘Hordes of excited children clustered around the working model of a mountain railway system with trains criss-crossing with intricate precision.’
    • ‘There is a lack of social services in neighborhoods where families with the most needs cluster together’
    congregate, gather, collect, group, come together, assemble
    View synonyms
    1. 1.1Statistics (of data points) have similar numerical values.
      ‘students tended to have marks clustering around 70 per cent’
      • ‘Standard deviation is the measurement of how scores are clustered or dispersed in relation to the mean.’
      • ‘However, peer group bias appears clustered with instrument manufacturer.’
      • ‘Although there were outliers, the majority of the data points clustered around the population mean.’
      • ‘We fitted town as a fixed effect and school as a random effect to allow for clustering at school level.’
      • ‘This method thus allows for clustering without a priori knowledge of the number of clusters present in the data set.’
      • ‘We have said that when multiple repeated tests are performed results will cluster around the ‘true’ value.’
      • ‘Average clustering coefficients and standard deviations of the averages for node degree bins are shown.’
      • ‘In both analyses, we computed robust standard errors adjusted for clustering at the firm level.’
      • ‘Standard errors have been adjusted for clustering within families.’
      • ‘Our analysis also ignored the fact that scores are clustered at practice level.’
      • ‘Similarly, in scientific data mining, algorithms seek to cluster, generalize, and classify patterns and correlations in databases.’
      • ‘However, while a few genes do show rather high transition bias, most of the estimates cluster tightly around the median value.’


Old English clyster; probably related to clot.