D defs.my
Entry 1 sense Webster, 1913

Trigonia

· Tri·go·ni·a · IPA
01 n. A genus of pearly bivalve shells, numerous extinct species of which are characteristic of the Mesozoic rocks. A few living species exist on…
  1. 1.
    A genus of pearly bivalve shells, numerous extinct species of which are characteristic of the Mesozoic rocks. A few living species exist on the coast of Australia.(Zool.)