Definition of triplet in US English:



  • 1usually tripletsOne of three children or animals born at the same birth.

    • ‘Six years before I was born, my mother gave birth to triplets: Felicity, Everett and Dillon.’
    • ‘I went there and saw the third lamb of a set of triplets being born.’
    • ‘There are 4,000 births of twins and triplets in Australia each year.’
    • ‘The rate of triplets born in Scotland did not follow the same trend, with 12 in 1999 compared to eight in 2003.’
    • ‘The three little girls settled in well and were the first triplets to attend that school.’
    • ‘The rate of triplet and higher-order multiple births has declined for the second year in a row, after large increases from 1980 to 1998.’
    • ‘The three cubs pictured above are believed to be the first set of polar bear triplets born in captivity.’
    • ‘I never expected them to be twins, let alone triplets or quadruplets.’
    • ‘We have excluded triplets and higher order births from all tables.’
    • ‘Half of all twins and most triplets are born preterm.’
    • ‘Since then, three sets of twins and a set of triplets have been born.’
    • ‘Rates of multiple births vary from country to country, but typically something like one in 7000 to 10000 births are naturally triplets.’
    • ‘A mother has beaten odds of one in 10,000 by giving birth to triplet boys after conceiving naturally.’
    • ‘If triplets or more were born, only two lambs were allowed to be reared with the dam, and the extra lambs were removed at 12 to 24 h of age and reared artificially.’
    • ‘Nearly 10,000 multiple births were recorded last year in the UK, and one in 35 children is now born as a twin, while triplet births have quadrupled in many countries.’
    • ‘Feeding more than one baby, dressing twins and triplets and buying children s equipment such as buggies are among the issues that will be under discussion.’
    • ‘Close to 60 percent of twins, over 90 percent of triplets and virtually all quadruplets and higher multiples are born preterm.’
    • ‘It would be safer for women to give birth in hospital if they were having twins or triplet or if their baby has a medical problem.’
    • ‘She did not become pregnant with the first three embryos but a second attempt using frozen embryos proved successful - and the couple were told that after years of waiting and hoping that they were expecting triplets.’
    • ‘In fact, triplets born to older mothers were actually less likely to experience poor birth outcomes than were triplets born to younger mothers.’
  • 2A set or succession of three similar things.

    • ‘Starting with a pair or triplet of markers, parametric approaches carry out local extension and perform local permutations of consecutive markers to produce the most likely marker order.’
    • ‘Single cards, pairs and triplets can be completed to quadruplets.’
    • ‘Proper diagnosis depends critically on accurate counts of the number of triplet repeats.’
    • ‘This work suggests that neither the number of available triplet codons nor the translational machinery itself represents a significant barrier to further expansion of the genetic code.’
    • ‘The reason why a triplet or quad of Aces is worth so few points is because they can be very easy to get.’
    • ‘DNA, RNA, and protein triplets or pairs were united on the basis of a high degree of similarity as detected by the appropriate blast algorithm or on the basis of annotation.’
    • ‘For example, M 3,2 is the number of triplet events affecting positions 2 and 3 of one codon and position 1 of the following codon.’
    • ‘Schools swim back and forth near shore at night, just outside the breaking waves, then split into pairs or triplets attached to one another, swimming toward the beach on a wave.’
    • ‘Small branch formulas or herb pairs or triplets are chosen to address prominent branch symptomology.’
    • ‘There are no other unlinked loci, nor are there any locus pairs or triplets that do not link to one of the nine linkage groups.’
    • ‘It constitutes a triplet, the first number representing the position, the second the wavelength and the third the transmission.’
    • ‘In general Keyword pairs or triplets are better than single keywords.’
    • ‘The third in the triplet took you in totally the opposite direction by looking at life as a transgender person who blurs the distinction between male and female identification.’
    • ‘The number of triplet repeats in normal individuals is 11-34.’
    • ‘The presence of an increased number of triplet repeat sequences is diagnostic for some single gene disorders.’
    1. 2.1Music A group of three equal notes to be performed in the time of two or four.
      • ‘Voicing in many pieces is made more advanced by placing the melody in the same hand as many moving sixteenth notes or triplets.’
      • ‘The arrows indicate the beginning of the grace note figure and the placement of each note in the triplet figure for the left hand.’
      • ‘All notes, rests, accidentals, articulations, triplets and staves are provided for the user.’
      • ‘In addition to quarters, eighths and sixteenth notes, triplets and dotted rhythms are used tastefully and add variety.’
      • ‘It also has some of the most tender passages Brahms ever wrote and a concluding series of halting triplets that is mesmerizing.’
    2. 2.2 A set of three rhyming lines of verse.
      • ‘That's to say, his poems build displacement into their structures: they move forward in discrete couplet and triplet units, they offer small bright pleasures and ask us to pass on quickly.’
      • ‘Fifty-two of these triplets would be published in 1977 as Finding Losses.’
      • ‘The verses of the Irish chapbooks are all in couplets but, in using the ‘liberty’ line, a pair of couplets is transformed into a triplet plus an isolated line.’
      stanza, strophe, stave, canto
      View synonyms
  • 3Physics Chemistry
    An atomic or molecular state characterized by two unpaired electrons with parallel spins.

    • ‘The photodynamic effect is accomplished mainly through the formation of singlet oxygen in the quenching of the sensitizer triplet state by ambient molecular oxygen.’
    • ‘The relatively stable ground state of oxygen is a triplet state with two unpaired electrons with the same spin quantum number, each located in different antibonding orbitals.’
    • ‘Such fields, however, do not wreck triplet superconductivity because the spins of both electrons may point in the same direction as the field.’
    • ‘Such electron transfer from the amine to the triplet ketone within a charge transfer complex is a well-established phenomenon.’
    • ‘A new reaction of this dye, whereby its excited triplet state oxidizes suitable electron donors, is now reported.’
    • ‘Our current hypothesis as to why these transfer functions vary within and across species boundaries is based on mechanistic differences between electron and triplet energy transfer.’
    1. 3.1 A group of three associated lines close together in a spectrum or electrophoretic gel.
      • ‘Because the Y base is located at position 37 adjacent to the anticodon triplet, its fluorescence is sensitive to any changes in the conformation and the binding state of the anticodon loop.’
      • ‘One central residue and its two selected supporting residues (one on each side) are together called a residue triplet.’
      • ‘The triplet and the quartet lines are clearly distinguished at the different spatial positions.’
      • ‘The analysis wavelength was 470 nm, near the maximum of the triplet difference spectra.’


Mid 17th century: from triple, on the pattern of doublet.