sphaeridium

English

Etymology

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

Noun

sphaeridium (plural sphaeridia)

(zoology) 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.

Part or all of this entry has been imported from the 1913 edition of Webster’s Dictionary, which is now free of copyright and hence in the public domain. The imported definitions may be significantly out of date, and any more recent senses may be completely missing.
(See the entry for “sphaeridium”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.)