monomyarian UK /ˌmɒnəˌmaɪˈɛəɹi.ən/US /ˌmɑnəˌmaɪˈɛɹi.ən/adjective 1noun 1forms 1 adjective1 •Of or relating to the Monomya, bivalves having only one adductor muscle. noun1 •A bivalve of this kind. formsmonomyarians