The Collaborative International Dictionary
Spermato-
Spermato- \Sper"ma*to-\, Spermo- \Sper"mo-\ Combining forms from Gr. spe`rma, -atos, seed, sperm, semen (of plants or animals); as, spermatoblast, spermoblast.
Douglas Harper's Etymology Dictionary
spermato-
before vowels spermat-, word-forming element meaning "seed, sperm," used from 1880s in scientific compounds, from comb. form of Greek sperma (genitive spermatos; see sperm).
Wiktionary
spermato-
pre. 1 Forms terms relating to seeds 2 Forms terms relating to sperm