Green’s Dictionary of Slang

lay it on v.

1. in senses of communication.

(a) to charge excessively.

[UK]Westmorland Gaz. 27 Apr. 4/5: Coachee [...] you needn’t be afeard of laying it on pretty thick .
[UK]Reading Mercury 6 Apr. 4/5: I intend to lay it on my customers pretty thick, or in other words, to tip it to them pretty stiff in my charges.

(b) to exaggerate; to make an excessive fuss.

[UK]E. Howard Jack Ashore III 273: It does my poor broken heart good to hear ye cuss that sodger – go it again, my daffydown-dilly, and lay it on thick.
[UK]A. Mayhew Paved with Gold 122: ‘You are a-laying it on,’ he answered impertinently; ‘one would think I was everything bad to hear you talk.’.
[UK]E.W. Hornung Black Mask (1992) 230: You did lay it on.
[UK]R. Llewellyn None But the Lonely Heart 96: ‘I mean a stork, Tiger,’ Henry says, laying it on a bit.
[US]B. Jackson Killing Time 177: I was laying it on just for the fun of it.
[US](con. 1973) C. Stella Johnny Porno 188: They put the hammer to her. ‘Turn informant or get used to munching muff the next dozen years’ [...] They laid it on thick.

(c) (orig. US) to criticize, to berate.

[US]O. Johnson Varmint 240: You laid it on pretty strong.
[US]Van Vechten Nigger Heaven 120: Now Dick, you’re laying it on pretty hard.
[NZ]F. Sargeson ‘Boy’ in A Man And His Wife (1944) 8: My father heard me answering my mother back, and oh gee if he didn’t lay it on.
[US]R. Price Ladies’ Man (1985) 163: Don’t lay it on me.
[US]J.L. Gwaltney Drylongso 225: From then on she really laid it on Miss Donnelly.

(d) (US black) to seek a verbal or physical confrontation, to hit.

[US]Big Joe ‘Rootin’ Ground Hog’ [lyrics] I’m a rootin’ ground hog babe, I roots everywhere I go / Lay it on me boy, it’s bad!
[US]K. Kolb Getting Straight 144: You’re flipping, and I should have had the guts to lay it on you straight when it first started.
[UK]T. Parker Frying-Pan 12: I picked up the cue [...] I was just going to lay it on him.

(e) to inform, to pass on information.

[US]A. Zugsmith Beat Generation 137: I’m going to lay it on you.
[US]D. Goines Inner City Hoodlum 111: Call Amos’ ol’ lady and lay it on her.
[US]E. Folb Runnin’ Down Some Lines 244: lay it on See break it down.
[US]‘Touré’ Portable Promised Land (ms.) 159: We Words (My Favorite Things) [...] Lay it on me. Layin in the cut. Let’s get it on.
[UK]K. Richards Life 267: ‘You Got the Silver’ [...] was one of the first ones I wrote entirely by myself and laid on Mick.
[US]S. King Finders Keepers (2016) 105: Go ahead. Lay it on me.

2. (US) to act or work efficiently or energetically.

[US]D. Runyon ‘The Defence of Strikerville’ in From First To Last (1954) 17: They might be calico rippers in real life, but they sure laid it on there.
[UK]A. Christie Murder in the Mews (1954) 62: The woman lays it on with a palette-knife.
[US]C.B. Davis Rebellion of Leo McGuire (1953) 16: Come on, kids, lay it on.
[US]Mezzrow & Wolfe Really the Blues 45: He really laid it on State Street.
[US]H. Selby Jr Last Exit to Brooklyn (1966) 185: Man, he shuh would like to bag that bitch and really lay it oner.
[UK]G.F. Newman You Flash Bastard 81: He realised his error in going easy on the man, he should have laid it on at his previous visit in court and got him the maximum.
[UK]M. Amis London Fields 176: Lay it on, but don’t overdo it.

3. (US black) to slap someone’s hand in greeting.

[US]H. Selby Jr Requiem for a Dream (1987) 19: Lay it on me jim – slap.