abranchial
/əˌbrænʧɪəl/Definitions
1. adjective
relating to or situated outside the branchial (gill) arches of a vertebrate embryo
“The abranchial region of the embryo develops into the heart and other vital organs.”
2. noun
a structure or organ that is derived from the abranchial region of a vertebrate embryo
“The abranchial body was an important discovery in the field of embryology.”