Green’s Dictionary of Slang

1. to do what is required, to join in.

1908		B. Fisher A. Mutt in Blackbeard Compilation (1977) 112: There’s a nice little poker game up in Jones’ room. Let’s kick in.
1913		J. London Valley of the Moon (1914) 42: Come on an’ kick in, you cold-feets. Get together.
1927		C. Coe Me – Gangster 267: I had kicked in with what the cops call corroboration.
1934		Wodehouse Right Ho, Jeeves 220: I should, as a man of honour and sensibility, have no choice but to come across and kick in.
1991		L. Bing Do or Die (1992) 18: My homeboys [...] They’ll just rape a girl, any girl, if she look good and she don’t wanna kick in.

2. to begin, to start to happen.

1908		K. McGaffey Sorrows of a Show Girl Ch. ii: Now that the first of the year has kicked in.
1978		J. Webb Fields of Fire (1980) 208: Before the draft kicked in, when we had what they called ‘true volunteers.’.
1999		K. Sampson Powder 66: If press starts to kick in the way we anticipate, all these funny little Record Collector readers are going to be helping themselves to two or three each.
2000		Guardian G2 1 Mar. 14: My drinking kicked in heavily at 17.

3. to (make something) start working, to accelerate an action, usu. of mechanical objects.

1972		WINS radio news 19 July n.p.: The generator kicks in when the power goes out [HDAS].
1997		N. Barlay Curvy Lovebox 89: The radio kicks in.
2000		Guardian 26 Jan. 12: It had fallen almost 400ft [...] when the safety system kicked in.
2001		N. Green Shooting Dr. Jack (2002) 29: As soon as it gets thick in here, the motor for that exhaust fan kick in.

4. of drugs, to take effect, to start to work; also of alcohol.

1981		J. Ellroy Brown’s Requiem 236: Getting into a cab outside the airport felt like four martinis kicking in.
c.1990		Herbert Huncke ‘Oral History of Benzedrine’ in Huncke Reader (1998) 341: People were uptight about sex [...] you know, once bennie kicked in . . . well, it teases you a little.
1998		I. Welsh Filth 79: The bennies are kicking in, so I’ll have to watch my gob.
2000		‘Eminem’ ‘Drug Ballad’ 🎵 (of alcohol) We used to mix Hen’ with Bacardi Dark / And when it, kicks in you can hardly talk.
2000		N. Griffiths Grits 64: Pure fuckin sulphate from Jed iss time [...] Kicks in quick, art thuddin, chewin me fuckin cheeks off, feel just fuckin fine.
2007		L. Redhead Cherry Pie [ebook] ‘Soon as these pills kick in we’re going to the cops’.

5. of a musical instrument.

1997

(con. 1970s) G. Pelecanos King Suckerman (1998) 27: The sun warming his face as the EWF horns kicked in.