MIRACIDIUM

[mi.ra.cid.i.um] n, pl -cid.ia [NL, fr. Gk meirak-, meirax youth, stripling + NL -idium] (1898): the free-swimming ciliated first larva of a digenetic trematode that seeks out and penetrates a suitable snail intermediate host in which it develops into a sporocyst -- mi.ra.cid.i.al adj