Definition of cusp in English:



  • 1A pointed end where two curves meet, in particular.

    • ‘Apparatus of at least three morphotypes (a, b, e) of simple coniforms with greatly elongated, curved to twisted cusps.’
    • ‘The protoloph meets the base of the protocone, not the cusp itself.’
    • ‘The enlarged surface and finer occlusion also permitted the development of complex series of subsidiary cusps and other accoutrements.’
    • ‘The edges of many of the sheets were rolled, and cusps formed where two oppositely scrolled edges met.’
    • ‘Concepts like century roses, starlines, cusps, Myiepan spores, among others which become clear by the end of the novel.’
    • ‘The cusp has a curved anterior margin and the base is short.’
    1. 1.1Architecture A moulded projection at the point of a small arch in Gothic tracery.
      • ‘Lingually, these cusps are flat or slightly concave from apex to base, while their labial sides are convex along their height and in cross section.’
      • ‘Fictive architectural molding, now incomplete but presumably once framing the image, rises between the two groups at the bottom to form an elongated trefoil with an ogival cusp.’
      • ‘From a high central half-round, the skirt descends along cyma or ogee curves to cusps that set off shallow arches with small half-rounds in the middle.’
      • ‘The crests are strongest at the apex of each cusp, and become weaker as they bifurcate or trifurcate towards the base of the crown.’
      • ‘Additional heraldic shields float in the foregrounds below the flanking scenes, as well as in the lancet cusps and the adjacent tracery openings above them.’
      • ‘Pronounced cusps at each side embellish the conventional New England Queen Anne vase splat design.’
      • ‘Weak crests run between the main cusp tip and the apex and along the posterior border. p4 is strongly asymmetric, with an extremely long posterolingual wing.’
      corner, intersection, point, apex, cusp
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    2. 1.2A cone-shaped prominence on the surface of a tooth.
      • ‘Given this level of fine control, it became possible, and advantageous, to evolve teeth with fixed and definite patterns of cusps.’
      • ‘The tooth is well worn with the individual cusps of each lobe indistinguishable.’
      • ‘However, they do have two parallel rows of cusps on their molariform teeth.’
      • ‘Strange cusps on the upper molars could be interpreted as either large neometaconules and paraconules, or lingually-displaced metacones and paracones with very large stylar cusps on the buccal shelf.’
      • ‘The numerous small teeth have three or five cusps, a unique characteristic among Pterosaurs.’
      • ‘Laterally, a shallow groove borders the lingual side of the tooth from the laterocone to the laterobasal cusp.’
      • ‘In the crown, the pulp has small conical extensions (pulp horns) into the cusps of the tooth, and in the root it extends along one or more canals to the tooth apex, where the nerves and blood vessels enter.’
      • ‘Lateral teeth are flatter and wider at the base of the cusp compared to anterior teeth and often lack lateral cusplets.’
      • ‘The cheek teeth have a W pattern of cusps and ridges, which is good for breaking up the insects they eat.’
      • ‘The peculiar cheek teeth, ornate with tiny, interlocking cusps, stand out boldly in their highly evolved but useless efficiency.’
      • ‘The second cusp is sometimes mistaken for an additional tooth.’
      • ‘Cheekteeth are brachydont, and their occlusal surfaces are made up of a series of cusps and basins or parallel enamel ridges.’
      • ‘Nobody doubted these were sharks' teeth, as they had two curved cusps and a well-developed root.’
      • ‘This matching of the cusps allowed the teeth to occlude, or meet, in a precision bite.’
      • ‘Each molar has three distinct cusps that interlock when their jaw is closed, forming a sieve for straining krill from the water.’
      • ‘The interlocking mechanism stabilized the molars, putting the lateral forces to work to scrape sharp, regular edges on the molar cusps rather than simply loosening the teeth over time.’
      • ‘The pattern of cusps in the definitive tooth is primarily controlled by timing.’
      • ‘Nevertheless, the parallel sequential budding characteristic of largest to smallest tooth cusps and vascular horns indicate that the two are closely correlated.’
      • ‘Instead, the cusps within the developing tooth arise as the result of a patterning cascade of control centers that ultimately direct the position, and timing, of both onset and offset of development.’
      • ‘Megadermatids lack upper incisors, and their large canines have a secondary cusp.’
    3. 1.3Anatomy A pocket or fold in the wall of the heart or a major blood vessel that fills and distends if the blood flows backwards, so forming part of a valve.
      • ‘Two dimensional echocardiography allows the assessment of valve structure and identifies thickening of cusps, leaflet prolapse, cusp fusion, and calcification.’
      • ‘The cusps of the external row are flat on their internal walls and rounded labially, while those of the middle row are four-sided anteriorly but become larger and more crescentic posteriorly.’
      • ‘Thus, the vein wall is inherently weak in varicose veins, which leads to dilatation and separation of valve cusps so that they become incompetent.’
      • ‘At the same time, these cusps get filled with blood, which then flows through the coronary arteries.’
    4. 1.4Mathematics A point at which the direction of a curve is abruptly reversed.
      • ‘Increasing the number of cusps, curves are produced that touch all n + 1 lines for greater n's.’
      • ‘The algorithms that Taubin developed worked well even in the vicinity of cusps and other singularities.’
      • ‘If the cusp of the cardioid is taken as the centre of inversion, the cardioid inverts to a parabola.’
      • ‘The pedal curve of the cissoid, when the pedal point is on the axis beyond the asymptote, at distance from the cusp four times that of the asymptote, is a cardioid.’
      bend, curve, arc, kink, dog-leg, crook, deviation, turn, turning, junction, fork, intersection
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    5. 1.5Each of the pointed ends of the crescent moon.
      • ‘This is measured from the Northern or Southern cusp of the Moon in the direction of the unlit part of the Moon.’
      • ‘The moon's cusps point toward the stars Pollux and Castor.’
      • ‘With my 10X50 binoculars, we were able to see Saber's Beads on the lower cusp of the moon.’
    6. 1.6Botany A sharp rigid point of a leaf.
      • ‘The recurve of the leaf blade will focus the sun's rays and increase the heat slightly within the leaf's cusp.’
  • 2Astrology
    The initial point of an astrological sign or house.

    ‘he was Aries on the cusp with Taurus’
    • ‘You do have Mars on the cusp of your 2nd house at 8 degrees Leo.’
    • ‘Mars is powerfully placed on the 4th house cusp.’
    • ‘You have Mars right on the cusp of your midheaven.’
    • ‘This good sense is shown by Saturn in Capricorn on the cusp of the 6th house opposing Sun-Venus in Cancer.’
    • ‘If there are no planets in a house, we observe the sign on the cusp of the house and ask what planet rules that sign.’
    • ‘The sign on the cusp and its ruler help to describe the locality of the item and in particular the quality of ground it lies upon.’
    • ‘Saturn, ruler of Aquarius on the cusp of the 9th house of ‘overseas travel’.’
    • ‘In fact, your Gemini solar return for this year has the sun placed exactly on the partnership house cusp, a positive sign for a relationship developing some time this year.’
    • ‘Mars sits on the cusp of his 6th house of illness.’
    • ‘Virgo on your 7th house cusp indicates that you do want a long-term, stable partnership, with someone you can trust and remain faithful to.’
    • ‘It is true that the sign on the cusp of the 7th house is an important clue to this and the influence of any planets within this house are also very important.’
    • ‘My Moon is at 2 degrees Sagittarius on the 4th house cusp.’
    • ‘Your relationship issues may remain a bit less clear for the next year or so, as Neptune has been sitting right on the cusp of your 7th house of partners.’
    • ‘In addition, the sign on the cusp of your 5th house of children is Virgo, another negative indicator.’
    • ‘It is described by the house that naturally governs that matter and it is signified by the planet that rules the cusp of that house.’
    • ‘It's not much used in modern astrology, to be honest, apart from as the cusp of the 7th house, the whole of the 7th house dealing with relationships.’
    • ‘The Moon on the cusp of the 5th house relates to the mother's concern for her daughter and acts as a general co-significator.’
    • ‘With Neptune on the 2nd cusp, no modern astrologer would be surprised to learn that he had no head for figures or account books.’
    • ‘One factor that largely determined the ancient recognition of house strength is the aspectual relationship that naturally exists between house cusps and the ascendant.’
    • ‘The 5th house cusp is almost exactly conjunct your son's natal 4 degree Pisces sun, so it is clear he is signified in this chart.’
  • 3A point of transition between two different states.

    ‘those on the cusp of adulthood’
    • ‘It is one of rapid change, on the cusp of something new, different, and exciting.’
    • ‘It carries the simple and honest pleasure of infant laughter and the wonder of watching a new mind on the cusp of a profound understanding: things don't disappear when you can't see them.’
    • ‘He is also a black man coming-of-age on the cusp of two shockingly different decades, the 1950s and the 1960s.’
    • ‘One of the annoying things about the indie world is having to be on the cusp of whatever is brand new.’
    • ‘Mind you, sometimes, now and again, Nature confounds us by letting an early break of fair skies extend itself a little, hover on the cusp of change and then, once the weather men are completely confused, settle in for a long hot summer.’
    • ‘It teeters on the cusp of the Mediterranean, offering endless vistas of blue-green sea, bucketfuls of fresh air, and crumbling, salty buildings of the old town that still manage to retain their elegance.’
    • ‘Conceptually, the case-study firms are situated at a critical cusp between a regional production system with its division of labor and an international supply chain.’
    • ‘The paradox of the work's title tells of a world at the cusp of a new era, one characterized as ‘crepuscular.’’
    • ‘We are on the cusp of a great set of decisions around what will happen to the world's water.’
    • ‘It spotlights the 23-year-old Bob teetering on the cusp of acoustic folk music and the mind-expanding new horizons offered by acid, free verse and electricity.’
    • ‘I wanted to capture Ireland as it is now, on the cusp of this huge social change it's going through.’
    • ‘He's a man who likes to contemplate the cusp between the realistic and the fanciful.’
    • ‘In a city like Vancouver, straddling the cusp between becoming beautiful, and settling for uninspired drab, it is projects like this one that can tip it one way or the other.’
    • ‘‘The economy is virtually firing on all cylinders again, and is on the cusp of a new era,’ he says.’
    • ‘Burgon's right on a cusp: stodgy, well-built traditional orchestration on one hand, weirdo avant-garderies and period electronics on the other.’
    • ‘The disease saw him go from super-fit athletic to pain-racked and bloated from bouts of chemo and steroids; from a young man on the cusp of his grown-up life to someone doubting if he would ever see 30.’
    • ‘His 1945 inauguration was right at the cusp of the critical events that put an end to World War II.’
    • ‘This fashion conscious teenager, short fingernails perfectly painted in metallic baby blue, is a young girl but on the cusp of womanhood; a child still at the back of her own mind and absolutely so in the eyes of the law.’
    • ‘They're on the cusp of changing the focus of society from the young to the old.’
    • ‘‘We're right at the cusp of understanding this,’ said Sherry Willis of Pennsylvania State University.’


Late 16th century (in cusp): from Latin cuspis point or apex.