1660s, from Latin tricuspidem (nominative tricuspis) "three-pointed," from tri- (see tri-) + cuspis "point" (see cusp).
Entries linking to tricuspid
tri-
word-forming element meaning "three, having three, once every three," from Latin tres (neuter tria) or Greek treis, trias "three" (see three).
cusp n.
1580s, in astrology, "first entrance of a house in the calculation of a nativity," from Latin cuspis "point, spear, pointed end, head," which is of unknown origin. Astronomical sense is from 1670s, "point or horn of a crescent." Anatomical sense of "a prominence on the crown of a tooth" is from 1839.