Source : Webster's Revised Unabridged Dictionary (1913)

Spermatoon \Sper`ma*to"["o]n\, n.; pl. {Spermatoa}. [NL., fr.
   Gr. spe`rma, -atos, seed + ??? an egg.] (Anat.)
   A spermoblast. -- {Sper`ma*to"al}, a. --Owen.