noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   Synonym of capitulum.
2. 2
   A sense organ found on the exterior of most sea urchins, consisting of an oval or spherical head surmounting a short pedicel. It is generally supposed to be an olfactory organ, or for equilibrium.

Synonyms

All synonyms

capitulum

Etymology

From Ancient Greek σφαιρίδιον (sphairídion, “sphere (diminutive form)”), by surface analysis, sphero- + -idium.

Related phrases

sea urchinsense organ

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.