any member of the genus Paramecium
A genus of ciliate protozoa that is often large enough to be seen by the naked eye. Paramecia are commonly used in genetic, cytological, and other research.
par-a-m[=e]'si-um, n. an infusorian in pond water or vegetable infusions--also Slipper Animalcule:--pl. PARAM[=E]'CIA. [Gr. param[=e]k[=e]s, long-shaped, para, beside, m[=e]kos, length.]