Cid·a·roi·da | \ ˌsidəˈrȯidə \
Definition of Cidaroida
: the oldest surviving order of sea urchins containing the most primitive of living forms, all lacking peristomial gills and sphaeridia but having an apically located anus — see cidaridae
Love words? Need even more definitions?Merriam-Webster unabridged
Words at Play
“In Vino Veritas” and Other Latin Phrases to Live By
Top 10 Latin Phrases
10 Polite Words for Impolite People
'Smatchet', 'Fustilugs', and more
Is It 'Home In' or 'Hone In'?
Both are used, but home in does a better job of...
Merriam-Webster's Words of the Week - Jan. 21
From the week ending 1/21/2022
Ask the Editors