The Collaborative International Dictionary
Cnidae
Cnida \Cni"da\ (n[imac]"d[.a]), n.; pl. Cnid[ae] (n[imac]"d[=e]). [NL., fr. Gr. kni`dh nettle, sea nettle.] (Zo["o]l.) One of the peculiar stinging cells found in C[oe]lenterata; a nematocyst; a lasso cell. [1913 Webster] ||
Wiktionary
cnidae
n. (plural of cnida English)