|See also shipworm any marine bivalve of the family Pholadidae, boring into rock, clay, or wood by means of sawlike shell valves|
|[C19: origin uncertain]|
|a fool or simpleton; ninny.|
|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
any of the marine bivalve mollusks of the family Pholadidae (Adesmoidea). Worldwide in distribution, they are especially adapted for boring into rock, shells, peat, hard clay, or mud. Most species occur in the intertidal zone, a few in deeper water.
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