BRANCHIAL
branchial
(adjective) of or relating to gills (or to parts of the body derived from embryonic gills)
Source: WordNet® 3.1
Etymology
Adjective
branchial (not comparable)
Of, pertaining to, or resembling gills or the embryonic branchial arches and clefts.
Noun
branchial (plural branchials)
A branchial arch
Source: Wiktionary
Bran"chi*al, a. (Anat.)
Definition: Of or pertaining to branchiæ or gills. Branchial arches, the
bony or cartilaginous arches which support the gills on each side of
the throat of fishes and amphibians. See Illustration in Appendix.
– Branchial clefts, the openings between the branchial arches
through which water passes.
Source: Webster’s Unabridged Dictionary 1913 Edition