Source : Webster's Revised Unabridged Dictionary (1913)

Ootheca \O`["o]*the"ca\, n.; pl. {O["o]thec[ae]}. [NL., fr. Gr.
   ? an egg + ? a case.] (Zo["o]l.)
   An egg case, especially those of many kinds of mollusks, and
   of some insects, as the cockroach. Cf. {O[oe]cium}.