branchial arch
nounMedical Definition of branchial arch
: one of a series of bony or cartilaginous arches that develop in the walls of the mouth cavity and pharynx of a vertebrate embryo, consist typically of a curved segmented bar or rod on each side meeting the contralateral bar or rod at the ventral end, and correspond to the gill arches of fishes and amphibians
— called also pharyngeal arch, visceral arch