animalcule

1. A small animal, as a fly, spider, etc. [Obs.] Ray. 2. (Zoöl.) An animal, invisible, or nearly so, to the naked eye. See Infusoria. Note: Many of the so-called animalcules have been shown to be plants, having locomotive powers something like those of animals. Among these are Volvox, the Desmidiacæ, and the siliceous Diatomaceæ. Spermatic animalcules. See Spermatozoa.

Source: Webster's Revised Unabridged Dictionary (1913), United States public domain. See methodology for full licensing detail. Word validity for game play may differ from any official game dictionary.