Green’s Dictionary of Slang

1. a party or get-together.

[1876		Mercury (Hobart, Tas.) 3 Jan. 3/5: A clam bake given at City Island by Congressman Odell].
[1882		G.A. Sala in Living London (1883) Nov. 521: They impart the element of relaxation into every one of their social observances, from ‘clam-bakes’ to ‘church oyster stews’].
[1905		‘Central Connecticut Word-List’ in DN III:i 5: clam-bake, n. A kind of picnic where the principal part of the meal consists of clams baked on the ground].
1909		‘O. Henry’ Roads of Destiny 306: I’m going to have the biggest clam-bake down on the beach.
1920		Ade Hand-made Fables 89: He looked like a Vessel Unloader who had put on a Mail Order Suit in order to attend a Clam Bake.
1929		S. Lewis Dodsworth 137: It was pleasant, on a clam bake at Momauguin, to loll in the sand with the general, a college president, and two steel kings.
1938		R. Hyde Nor the Years Condemn 285: Must ’a been a grand old clam-bake for the grand old Southern town.
1948		G.H. Bean Yankee Auctioneer 37: Most likely it is used at clam bakes or for holding home brew.
1959		J. Blake letter 6 Aug. in Joint (1972) 143: Are you going to that enormous Hefner clambake?
1966		‘Tom Pendleton’ Iron Orchard (1967) 286: God, what a clam-bake. I came for laughs, but it’s really kind of embarrassing.

2. (US black/jazz) a spontaneous musical session.

1935		Charleston (WV) Daily Mail 27 June 8/8: A ‘clam bake’ [...] is a musical free-for-all in which each man toots at will but tries to maintain some semblance of harmony.
1944		Cab Calloway New Hepsters Dict. in Calloway (1976) 253: clambake (n.): ad lib session, every man for himself, a jam session not in the groove.
1952		B. Ulanov Hist. of Jazz in America 359: clambake: earlier used synonymously (and honorifically) with ‘jam session,’ later descriptive of an improvised or arranged session which doesn’t come off.
1956		S. Longstreet Real Jazz Old and New 149: A clambake is a jam session [W&F].

3. (US) an event, esp. one that fails to live up to the obvious efforts that have been put into its preparation.

1930		M. Fiaschetti You Gotta Be Rough 276: [of infiltrating the US Mafia] ‘Mike,’ I said to myself, ‘you’ll learn a few things before you’re through with this clambake, only here’s hoping it won’t be a lesson in ‘Safety First’ for your successor’ .
1939		in W.C. Fields By Himself (1974) 330: When this clam-bake folds up in the Fall, I’m going out to Leadville and open a honky-tonk.
1947		S.J. Perelman Westward Ha! 117: The sort of sickly good-fellowship that prevails at a department-store clambake.
1958		(con. 1950) E. Frankel Band of Brothers 177: Last time around everybody was involved. Not this Korean clambake.
1960, 1975		Wentworth & Flexner DAS.

4. a brawl, a fight.

1944

R.L. Bellem ‘Murder’s Mouthpiece’ Hollywood Detective Aug. 🌐 I can handle my own clambakes, see?