gill bar vs branchial arch

gill bar and branchial arch both are nouns.

Word	Noun	Adjective	Verb	Adverb
gill bar	Yes	No	No	No
branchial arch	Yes	No	No	No

As nouns, gill bar and branchial arch are synonyms defined as:

gill bar and branchial arch: one of the bony or cartilaginous arches on each side of the pharynx that support the gills of fishes and aquatic amphibians

Other synonyms of gill bar include gill arch.

gill bar (noun)	branchial arch (noun)
one of the bony or cartilaginous arches on each side of the pharynx that support the gills of fishes and aquatic amphibians	one of the bony or cartilaginous arches on each side of the pharynx that support the gills of fishes and aquatic amphibians