Source : Webster's Revised Unabridged Dictionary (1913)

Infusory \In*fu"so*ry\, a. (Zo["o]l.)
   Infusorial.

Infusory \In*fu"so*ry\, n.; pl. {Infusories}. (Zo["o]l.)
   One of the Infusoria; -- usually in the pl.