Definition of "clam"

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. Lincoln, chapter 3, in Mr. Pratt's Patients

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 solution

1970, “Cherrystones”, in Outlaw, performed by Eugene McDaniels

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)

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

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

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

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

The clam of death.

1837, Thomas Carlyle, The French Revolution: A History […], volumes (please specify |volume=I to III), London: Chapman and Hall, (please specify the book or page number)

A chilling sweat , a damp of jealousy,Hangs on my brows, and clams upon my limbs

1690, [John] Dryden, Amphitryon; or, The Two Sosia’s. […], London: […] J[acob] Tonson, […]; and M. Tonson […], published 1691, (please specify the page)

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, […]