—n. 1. any of various bivalve mollusks, esp. certain edible species. Cf. quahog, soft-shell clam. 2. Informal.a secretive or silent person.
4. Slang.a dollar or the sum of a dollar: I only made 60 clams a week.
—v.i. 1. to gather or dig clams.
2. clam up,Slang.to refuse to talk or reply; refrain from talking or divulging information: The teacher asked who had thrown the eraser, but the class clammed up.