synotia

https://doi.org/10.1351/goldbook.11279

Congenital malformation characterized by the union or approximation of the ears in front of the neck, often accompanied by the absence or defective development of the lower jaw.

See also: agnathia, megagnathia, otocephaly
Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 810 (https://doi.org/10.1515/pac-2015-1202)