Definition of 'Tristoma'
- Tristoma \Tris"to*ma\ (tr[i^]s"t[-o]*m[.a]), n. [NL., from Gr. tri- (see Tri-) + sto`ma mouth.] (Zool.) Any one of numerous species of trematode worms belonging to Tristoma and allied genera having a large posterior sucker and two small anterior ones. They usually have broad, thin, and disklike bodies, and are parasite on the gills and skin of fishes. [1913 Webster]