Dictionary:

pelecypod

  (pə-lĕs'ə-pŏd')

See lamellibranch.

[From New Latin Pelecypoda, class name : Greek pelekus, ax + New Latin -poda, -pod.]

The noun has one meaning:

Meaning #1: marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together
  Synonyms: bivalve, lamellibranch

The adjective pelecypod has one meaning:

Meaning #1: bivalve
  Synonyms: lamellibranch, pelecypodous