(zoology) Any clam in the family Pisidiidae, now considered part of the Sphaeriidae.

(grammar) A noun consisting of a verb followed by a particle or preposition; the substantive counterpart of a phrasal verb (in grammar schemas that use that concept), conveying gerundive meaning.

(informal) A fraud; something carried out with the intention of deceiving, usually for personal, often illegal, gain.

a saying used of the difficulty of talking to someone who is not listening