1. a point or pointed end.
  2. Anatomy, Zoology, Botany. a point, projection, or elevation, as on the crown of a tooth.
  3. Also called spinode. Geometry. a point where two branches of a curve meet, end, and are tangent.
  4. Architecture. a decorative device, used especially in Gothic architecture to vary the outlines of intradoses or to form architectural foils, consisting of a pair of curves tangent to the real or imaginary line defining the area decorated and meeting at a point within the area.
  5. Astronomy. a point of a crescent, especially of the moon.
  6. Astrology.
    1. the zodiacal degree that marks the beginning of a house or a sign.
    2. Informal.a person born on the first day of a sign.
  7. a point that marks the beginning of a change: on the cusp of a new era.

Origin of cusp

First recorded in 1575–85, cusp is from the Latin word cuspis a point
Related formscusp·al, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for cuspal


  1. any of the small elevations on the grinding or chewing surface of a tooth
  2. any of the triangular flaps of a heart valve
  3. a point or pointed end
  4. Also called: spinode geometry a point at which two arcs of a curve intersect and at which the two tangents are coincident
  5. architect a carving at the meeting place of two arcs
  6. astronomy either of the points of a crescent moon or of a satellite or inferior planet in a similar phase
  7. astrology any division between houses or signs of the zodiac

Word Origin for cusp

C16: from Latin cuspis point, pointed end
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for cuspal



1580s, from Latin cuspis "point, spear, pointed end, head," of unknown origin. Astrological use is earliest.

Online Etymology Dictionary, © 2010 Douglas Harper

cuspal in Medicine


  1. Relating to a cusp.


  1. A pointed or rounded projection on the chewing surface of a tooth.
  2. A triangular fold or flap of a heart valve.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.