Entry 1 sense Webster, 1913 Brachiopoda · Brach·i·op·o·da · IPA 01 n. A class of Molluscoidea having a symmetrical bivalve shell, often attached by a fleshy peduncle. 1. A class of Molluscoidea having a symmetrical bivalve shell, often attached by a fleshy peduncle.(Zool.)