Green’s Dictionary of Slang

1. (orig. US, also lam, lamp up) to look at, to assess visually.

1896		F. Hutcheson Barkeep Stories 197: ‘De first t’ing I lamp to in de paper is w’ere dey’s a mob o’ stick-up guys breakin’ into booze joints around town’.
1904		Sydney Sportsman (Surry Hills, NSW) 11 May 1/1: Still lamping him I said, ‘What a memory you must have’.
1907		Lippincott’s Monthly Mag. (Phila.) Oct. 503: When I lamps on top to see what was going on, there was Fat .
1910		Spokane Press (WA) 22 Sept. 7/3: He stops to lamp up a bunch of red neckties in a glass front (shop window).
1913		H.G. van Campen ‘Life on Broadway’ in McClures Mag. Aug. 198/2: Flossie. Would you figger that a ball-player’s word could be took by a lady? Evangeline. I'd have to lamp his contract first.
1914		E. O’Neill The Movie Man in Ten ‘Lost’ Plays (1995) 190: There’s some class to some of the dames down here. You ought to have seen the bear I lamped this afternoon.
1921		N. Putnam West Broadway 200: When she lamped us she jumped to her feet and hurried over.
1929		M. Levin Reporter 377: Then Blackjack lamps Stew Hardy sitting by the table.
1937		C. Himes ‘A Nigger’ in Coll. Stories (1990) 32: Big Mama May [...] lamped the lain when he drew up.
1938		J. Curtis They Drive by Night 24: If a bogey lamped him he’d do him in two two’s. If you crossed the road too often they was bound to say you were loitering with intent to commit a felony.
1944		D. Burley Orig. Hbk of Harlem Jive 21: Thou hast more than a Cat can lam / In the reach of gim and gam.
1946		Mezzrow & Wolfe Really the Blues 261: I lamped the engraved card he handed me.
1953		T.A.G. Hungerford Riverslake 168: Lamp his eyes – he’s like a half-baked Chow.
1959		‘Don Elliott’ Gang Girl (2011) 24: They looked them [i.e. magazines] over for free, lamping the pictures and putting them back in the rack.
1962		R. Cook Crust on its Uppers 28: Bent poker games with Marchmare and me lamping each other’s broads.
1969		P. Boyle All Looks Yellow to the Jaundiced Eye 53: What Blondie is really doing at the hand basins is lamping the establishment.
1971		J. McNeill Chocolate Frog (1973) 43: tosser: We’ve seen more’n you’ll ever lamp...shitman!
1979		F. Norman Too Many Crooks Spoil the Caper 156: Then he lamped me in no uncertain terms.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 7: ‘What is the ask?’ he said as he lamped her pointed brace and bits poking out from the skimpy dicky dirt showing her bare comic cuts.
1990		S. Morgan Homeboy 264: The Chinese gangster just lamped him with a freezedried smile.
1999		D. Healy Sudden Times 239: He’s lamping me. It’s tricky.
2002		R.G. Barrett Mystery Bay Blues 56: The boke seemed friendly enough and he hadn’t lamped Les from the fight.
2006		D. Winslow Winter of Frankie Machine (2007) 77: You didn’t see a lot of guys in suits and ties on the dock, so Frank lamped Bap right away as something different.
2015		L. McInerney Glorious Heresies 93: [S]he lamps her piebald toes.

2. to consider, to think about [the image is of watching other people].

1954		J. Phelan Tramp at Anchor 151: I had ‘lamped a stoppo’ — i.e., I had been hoping to escape.
1997–2000		Da Bomb 🌐 17: Lamping: To daydream.

3. (US black/campus) to loiter, to ‘hang out’, to relax while others panic.

1988		G. Tate ‘Public Enemy’ in Flyboy in the Buttermilk (1992) 131: Ice-T and Big Daddy Kane are lamping by a limo.
1995		L. Stavsky et al. A2Z 62/2: We wasn’t loitering nothin’, Officer; we just lampin’.
2000		Hip-Hop Connection Jan./Feb. 54: To ‘lamp’ or be ‘lampin’ isn’t in very common usage these days [...] it was Flavor who single-handedly popularised this phrase on the Public Enemy track ‘Flavor Flav Cold Lampin’, which means to chill out and relax.
2012		The Game ‘They Don’t Want None’ 🎵 Lampin in Belize, Louis Vuitton duffel bags.