Entry 1 sense Webster, 1913 Hypobranchial · Hy·po·bran·chi·al · IPA 01 a. Pertaining to the segment between the basibranchial and the ceratobranchial in a branchial arch. 1. Pertaining to the segment between the basibranchial and the ceratobranchial in a branchial arch.(Anat.)