- In embryology, one of several arches, resembling the gill arches of a fish, found in the embryo of a higher vertebrate; these arches develop into structures of the ear and neck.
- In biology, one of several bony or cartilaginous arches located on either side of the pharynx and supporting the gills in fish and amphibians.
Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 731 (https://doi.org/10.1515/pac-2015-1202)