monomyarian
/ˌmɒnə(ʊ)mʌɪˈɛːrɪən/Zoology
adjective
Of a bivalve mollusc: having only one (posterior) adductor muscle; relating to or characteristic of such a mollusc. Formerly also: †belonging to the former group Monomyaria of bivalves ( obsolete ).
noun
A bivalve mollusc of a type having only one (posterior) adductor muscle (e.g. an oyster).
Origin
Mid 19th century. From monomyary + -an; compare -ian.