Etymology From Middle English clam (“pincers, vice, clamp”), from Old English clam (“bond, fetter, grip, grasp”), from Proto-West Germanic *klammjan (“press, squeeze together”). The sense “dollar” may allude to wampum. The sense "Scientologist" alludes to the Scientologist belief that human thetans (souls) previously inhabited clams.
A bivalve mollusk of many kinds, especially those that are edible; for example soft-shell clams (Mya arenaria), hard clams (Mercenaria mercenaria), sea clams or hen clams (Spisula solidissima), and other species, possibly originally applied to clams of species Tridacna gigas, a huge East Indian bivalve.
My hopes wa'n't disappointed. I never saw clams thicker than they was along them inshore flats. I filled my dreener in no time, and then it come to me that 'twouldn't be a bad idee to get a lot more, take 'em with me to Wellmouth, and peddle 'em out. Clams was fairly scarce over that side of the bay and ought to fetch a fair price.1913, Joseph C[rosby] Lincoln, chapter III, in Mr. Pratt’s Patients, New York, N.Y.; London: D[aniel] Appleton and Company, →OCLC:
Long as I have my clams I don't give a damn about revolution / Long as I have my rice I don't have to think twice about a solution1970, “Cherrystones”, in Outlaw, performed by Eugene McDaniels:
2
Historical, In plural A type of strong pincers or forceps.
The network canceled—nonco-operation their legal shysters said. Suing me, for, for ten million clams, damages to sponsors, agencies.1973, Lucas Webb, Stribling, page 188:
So the clams have John Travolta, Tom Cruise, et al in their hot li'l ol'P-R hands […]1998 February 23, jesparolini, “CO$ Celebrities: USEFUL IDIOTS”, in alt.religion.scientology (Usenet):
You had too many fucking days off, and you think this is a game? You think I'm the only one that's going to work up there while you motherfuckers sit out there and clam all over this fucking joint? What do you think this is anyhow? What kind of playing do you think this is? What kind of miscues do you call this?... You afraid you won't be heard? Everybody can hear your fucking clams out there. You don't need a mic for that. You taking up too much time blowing what? Shit! You stand out here all fucking night trying to blow your brains out. When it comes time to play, what do you play? Clams?! You got nowhere to fucking go the next day. I hear one fucking clam from anybody, you've had it! One clam and this whole fucking band is through tonight. Try me!1980s, Buddy Rich, bus recording of Buddy Rich by pianist Lee Musiker, YouTube:
8
Informal One who clams up; a taciturn person, one who refuses to speak.
9
US, Dated, Slang mouth (Now found mostly in the expression shut one's clam)
Why, he hasn't opened his clam since that morning in your room. I expected he would hold forth on every and all occasions.1900, Burt L. Standish, Frank Merriwell's Tricks: Or True Friends and False:
Jason wouldn't shut his clam about the invaders.2017, Benjamin Kane Ethridge, Dungeon Brain:
Etymology From Middle English clam (“pincers, vice, clamp”), from Old English clam (“bond, fetter, grip, grasp”), from Proto-West Germanic *klammjan (“press, squeeze together”). The sense “dollar” may allude to wampum. The sense "Scientologist" alludes to the Scientologist belief that human thetans (souls) previously inhabited clams.
Etymology From Middle English clammen, clemen (“to smear, bedaub”), from Old English clǣman (“to smear, bedaub”). Cognate with German klamm (“clammy”). See also clammy (“damp, cold and sticky”) and clem (“to adhere, stick, plug (a hole)”).
Ice is said to be clam, when beginning to melt with the sun or otherwise, and not easy to be slid upon.1808, John Jamieson, An Etymological Dictionary of the Scottish Language:
A crash or clangor made by ringing all the bells of a chime at once.
By the bells standing too long in leading compass, the rest are thrown and jumbled together; whereby claps and clams so unpleasing to the hearers are occasion'd.1702, Campanologia Improved:
clam
verb
1
To produce, in bellringing, a clam or clangor; to cause to clang.
When they [bells] lie fifths thus 1 5 2 6 3 7 4 8, 'tis then most pleasant and excellent music to clam them; that is, the two notes of each concord to strike together, and if they be clam'd true the eight bells will strike like four, but with far greater musick and harmony.1702, Campanologia Improved:
clam
noun
Etymology From Middle English clammen, clemen (“to smear, bedaub”), from Old English clǣman (“to smear, bedaub”). Cognate with German klamm (“clammy”). See also clammy (“damp, cold and sticky”) and clem (“to adhere, stick, plug (a hole)”).
1
clamminess; moisture
The clam of death.1837, Thomas Carlyle, The French Revolution: A History […], volume (please specify |volume=I to III), London: Chapman and Hall, →OCLC, (please specify the book or page number):
clam
verb
Etymology From Middle English clammen, clemen (“to smear, bedaub”), from Old English clǣman (“to smear, bedaub”). Cognate with German klamm (“clammy”). See also clammy (“damp, cold and sticky”) and clem (“to adhere, stick, plug (a hole)”).
1
To be moist or glutinous; to stick; to adhere.
A chilling sweat , a damp of jealousy, Hangs on my brows, and clams upon my limbs1690, [John] Dryden, Amphitryon; or, The Two Sosia’s. […], London: […] J[acob] Tonson, […]; and M. Tonson […], published 1691, →OCLC, (please specify the page):
2
To clog, as with glutinous or viscous matter.
A whole Swarm of Wasps got into a Hony-pot, and there they Cloy'd and Clam'd themselves till there was no getting Out again.1692, Roger L’Estrange, “ (please specify the fable number.) (please specify the name of the fable.)”, in Fables, of Æsop and Other Eminent Mythologists: […], London: […] R[ichard] Sare, […], →OCLC: