Alimentary is an adjective that comes from the the Latin word for food, alimentum. The alimentary canal, also known as the digestive tract, is a tube extending from mouth to anus that's about 20 feet long (and typically longer in cadavers because of a loss of smooth muscle tone that occurs after death)

The Terminologia Anatomica, with futility, prefers alimentary system instead of digestive system.

The Indo-European root of alimentum is al, "to grow", giving rise to the Latin alere, "to nuture", from which developed alma mater (nourishing mother), alumnus (one who has been nourished), alimony (money for nourishment), and adult (one who has grown up thanks to nourishment; the "ul" in adult is derived from "al").