- to gather or dig clams.
- 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.
Origin of clam1
- (intr, adverb) informal to keep or become silent or withhold information
- any of various burrowing bivalve molluscs of the genera Mya, Venus, etc. Many species, such as the quahog and soft-shell clam, are edible and Tridacna gigas is the largest known bivalve, nearly 1.5 metres long
- the edible flesh of such a mollusc
- informal a reticent person
- (intr) mainly US to gather clams
- a variant of clem
Word Origin and History for clam up
bivalve mollusk, c.1500, in clam-shell, originally Scottish, apparently a particular use from Middle English clam "pincers, vice, clamp" (late 14c.), from Old English clamm "bond, fetter, grip, grasp," from Proto-Germanic *klam- "to press or squeeze together" (cf. Old High German klamma "cramp, fetter, constriction," German Klamm "a constriction"). If this is right then the original reference is to the shell. Clam-chowder attested from 1822. To be happy as a clam is from 1833, but the earliest uses do not elaborate on the notion behind it, unless it be self-containment.
"to dig for clams," 1630s, American English, from clam (n.). Clam up "be quiet" is 1916, American English, but clam was used in this sense as an interjection mid-14c.
Idioms and Phrases with clam up
Refuse to talk or respond, as in Whenever she asks her teenager about his activities, he clams up. This term alludes to the tightly closed valves of a live clam. [Slang; early 1900s]