Definition of cusp in English:

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Pronunciation: /kʌsp/


1A pointed end where two curves meet, in particular:
Example sentences
  • Apparatus of at least three morphotypes (a, b, e) of simple coniforms with greatly elongated, curved to twisted cusps.
  • The cusp has a curved anterior margin and the base is short.
  • The enlarged surface and finer occlusion also permitted the development of complex series of subsidiary cusps and other accoutrements.
1.1 Architecture A moulded projection at the point of a small arch in Gothic tracery.
Example sentences
  • 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.
1.2A cone-shaped prominence on the surface of a tooth.
Example sentences
  • 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.
  • 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.
1.3 Anatomy 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.
Example sentences
  • At the same time, these cusps get filled with blood, which then flows through the coronary arteries.
  • Thus, the vein wall is inherently weak in varicose veins, which leads to dilatation and separation of valve cusps so that they become incompetent.
  • 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.
1.4 Mathematics A point at which the direction of a curve is abruptly reversed.
Example sentences
  • Increasing the number of cusps, curves are produced that touch all n + 1 lines for greater n's.
  • If the cusp of the cardioid is taken as the centre of inversion, the cardioid inverts to a parabola.
  • The algorithms that Taubin developed worked well even in the vicinity of cusps and other singularities.
1.5Each of the pointed ends of the crescent moon.
Example sentences
  • This is measured from the Northern or Southern cusp of the Moon in the direction of the unlit part of the Moon.
  • With my 10X50 binoculars, we were able to see Saber's Beads on the lower cusp of the moon.
  • The moon's cusps point toward the stars Pollux and Castor.
1.6 Botany A sharp rigid point of a leaf.
Example sentences
  • The recurve of the leaf blade will focus the sun's rays and increase the heat slightly within the leaf's cusp.
2 Astrology The initial point of an astrological sign or house: he was Aries on the cusp with Taurus
More example sentences
  • In addition, the sign on the cusp of your 5th house of children is Virgo, another negative indicator.
  • 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.
  • Saturn, ruler of Aquarius on the cusp of the 9th house of ‘overseas travel’.
3A point of transition between two different states: those on the cusp of adulthood
More example sentences
  • He is also a black man coming-of-age on the cusp of two shockingly different decades, the 1950s and the 1960s.
  • It is one of rapid change, on the cusp of something new, different, and exciting.
  • ‘The economy is virtually firing on all cylinders again, and is on the cusp of a new era,’ he says.



Pronunciation: /ˈkʌspeɪt/
Example sentences
  • Their macrostructures are similar to those of present-day soils, with pseudo-anticlinal structures and cuspate structures comparable to those produced by the expansion and contraction of swelling clays.
  • The asymmetry of folds at shallower levels in the overburden sequence suggest that the original anticlinal ridges at the base of the overburden sequence were cuspate.
  • The linear to cuspate sinter rim locally projects up to 30 cm over the water surface.


Example sentences
  • Rajasthani palaces with their open-sided rooms and fluid spaces were admirably adapted to the hot, dry climate, and the ornamental features such as cusped arches and bangladar roofs represent a fusion of Hindu and Mughal styles.
  • The mihrab arch was cusped into the same trefoil shape as the club-symbol on a pack of playing cards, while the capitals were carved with a band of kufic commemorating the building of the mosque eight hundred years previously.
  • In the older bazaars, the great cusped gateways of the old Hyderabadi havelis still stand, but now lead nowhere, except to a half-built matrix of foundations and concrete piles.


Pronunciation: /ˈkʌspɪdeɪt/
Example sentences
  • The premolars are characteristically very slender, sharp, and cuspidate.
  • A gland cell is often associated with a sensory spot, a cuspidate spine, a seta, or an adhesive spine in segment 4 of male Pycnophyes and Kinorhynchus.
  • The ridge summit is usually worn along its length, but on UALVP 22646 and ROM 05624, much of it is unworn and seen to be weakly cuspidate, with up to three poorly developed cuspules or thickenings along the summit.


Pronunciation: /ˈkʌspɪd(ə)l/


Late 16th century (in sense 2): from Latin cuspis 'point or apex'.

  • When we say someone is on the cusp of something we mean that they are at a point of transition between two states. This probably comes from the astrological use of cusp as the term for the division between one astrological sign and another. The word comes from Latin cuspis, meaning ‘a point’, and can also be applied to the pointed end where two curves meet, such as the tip of a crescent moon.

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