Compare Byzantine Greekζῳοειδής resembling an animal, and also Frenchzooïde (of a mineral) that bears the fossilized imprint of an animal (1842).
Meaning & use
Obsolete. rare.
1849
Resembling an animal, esp. in being motile.
1849
Thus, if we examine several of the families of Chlorospermeæ.., we find numerous zooid plants, some of the simplest forms in the organic kingdom, consisting of single rows of organic cells, enveloped in a mucoid substance, and swimming in water.
J. Leidy in American Journal of Medical Sciencevol. 17 287
1849
Cells..accumulate and fix around and within themselves certain matters which they derive from the surrounding nutritive fluids, as happens in the case of many zooid plants.