any of a genus (Paramecium) of one-celled, elongated, slipper-shaped ciliates moving by means of cilia and having a backward-curving oral groove that ends with the mouth
See paramecium in American Heritage Dictionary 4
(părˌə-mēˈshē-əm, -sē-əm)
nounpl.par·a·me·ci·a(-shē-ə, -sē-ə) or par·a·me·ci·ums
Any of various freshwater ciliate protozoans of the genus Paramecium, usually oval and having an oral groove for feeding.