the front part of the alimentary canal in vertebrate embryos: the duodenum, stomach, esophagus, pharynx, etc. develop from it
See foregut in American Heritage Dictionary 4
noun
The anterior part of the embryonic alimentary canal of a vertebrate from which the pharynx, lungs, esophagus, stomach, liver, pancreas, and duodenum develop.
The first part of the alimentary canal of an arthropod or annelid, which includes the buccal cavity, esophagus, crop, and gizzard.