"bottom, depths; base of an organ," 1754, from Latin fundus "bottom" (see fund (n.)). In any general use it probably is extended from specific senses in anatomy.
Find fundus (Noun) in the Latin Online Dictionary with English meanings, all fabulous forms & inflections and a conjugation table: fundus, fundi, fundo, fundum...
Look up fundus in Wiktionary, the free dictionary. Fundus (Latin for "bottom") is an anatomical term referring to that part of a concavity in any organ...