PERISTAL'TIC, adjective [Gr. to involve.] Spiral; vermicular or worm-like. The peristaltic motion of the intestines is performed by the contraction of the circular and longitudinal fibers composing their fleshy coats, by which the chyle is driven into the orifices of the lacteals, and the excrements are protruded towards the anus.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI