Webster’s Revised Unabridged Dictionary · 1913
Spermatheca
Sper′ma·the′ca, n.; pl. Spermathecæ (#). [NL., from Gr. σπέρμα seed + θήκη case, or receptacle.] (Zoöl.) A small sac connected with the female reproductive organs of insects and many other invertebrates, serving to receive and retain the spermatozoa.