Green’s Dictionary of Slang

1. to see, to recognize, to notice, to watch, to understand, to work something out.

1911		‘Sing Sing No. 57,700’ My View on Books in N.Y. Times Mag. 30 Apr. 5/5: The First Violin Jessie Fothergill [...] We have a hunch that Jessie is there plenty strong every time, even if this [title] is the only one we have clocked.
1929		J. Lait Broadway Melody 68: I was clocking that start those high-steppers just tried out. I think I got their angle from my slant.
1938		D. Runyon ‘A Piece of Pie’ in Runyon on Broadway (1954) 682: She is clocked by many experts.
1959		F. Norman Fings II i: I looks around ter clock the sound – it’s Jack the Prince’s mob.
1968		K. Brasselle Cannibals 24: I promised myself to buy Gina a Russian sable if I had clocked this situation wrong.
1979		E. Torres After Hours 7: He’d clocked me early.
1983		S. Gee Never in My Lifetime in Best Radio Plays (1984) 60: Even now, here with you, I’m scanning the park, clocking.
1994		R.P. McNamara Times Square Hustler 55: You always gotta be clockin’ [...] the man to make sure he ain’t Five-0.
1999		K. Sampson Powder 4: She clocked the accompanying shot of Helmet and snorted.
2001		Indep. on Sun. Rev. 15 Apr. 53: He clocked the barman as some sort of dago.
2011		G. Knight Hood Rat 110: Must have clocked us as we were parking up and took off.
2013		D. Whish-Wilson Zero at the Bone [ebook] No point lying. She had clocked him for an investigator.
2018		I. Welsh Dead Man’s Trousers 80: Clocked by a sexy hostess.
2020		G. Krauze Who They Was 3: I clock she’s got a big diamond ring on her wedding finger.
2020		D. Whish-Wilson Shore Leave 29: [A] thin hairy man [...] exit the toilet, clock them and grimace.
2022		J. Hannaham Didn’t Nobody Give a Shit 150: [H]oping that [...] Paul hadn'’ clocked her ‘unconventional gender identity’ .

2. to look at.

1917		Van Loan ‘By a Hair’ in Old Man Curry 80: Elisha worked fine this morning. I clocked him myself .
1935		R. Chandler ‘Nevada Gas’ in Spanish Blood (1946) 140: I like to clock the ponies.
1949		Monteleone Criminal Sl. (rev. edn).
1953		T. Williams Camino Real Block Twelve : Here! Clock him!
1958		F. Norman Bang To Rights 70: When he saw that I was clocking him he asked me if I wanted a bit.
1963		L.F. Freed Crime in S. Afr. 105: He clocked to the left, he clocked to the right.
1979		E. Torres After Hours 79: I’m clocking the scene.
1982		P. Bailey An Eng. Madam 70: He wasn’t clocking me the way blokes clock you when they want to get your knickers off.
1988		J. Healy Grass Arena (1990) 152: She got up slowly, saw me clocking her legs.
1999		Observer Rev. 28 Nov. 5: A panhandler clocked the monstrously big statuette and said: ‘That’s an Emmy. Congratulations!’.
2000		Hip-Hop Connection Jan. 94: Like when you do a chrome and everyone’s clocking it, but they have no idea it’s by you.
2004		J. McCourt ‘Vilja de Tanquay Exults’ in Queer Street 301: She’s been clocking her seniors in the ’Dilly.
2010		L. Redhead Thrill City [ebook] Soon as I clocked him I ran out of the function room.
2011		J.J. Connolly Viva La Madness 61: The CCTV’s clockin ya.
2013		J. Stahl Happy Mutant Baby Pills 138: Watch your step, I think somebody’s clocking us from the window.

3. to hit, usu. in the face.

1929		News-Pictorial (Perth) 15 Nov. 2/1: It was an expensive punch that Sarior Cacciottoko [...] gave Jack Thomas [...] The defendant [...] outlined the quarrel in brief and concluded with: ‘Well, Your Worship, I just clocked him!’.
1930		Geraldton Guardian (WA) 23 July 4/6: He got into an argument with, a native policeman, and, as he admitted [...] ‘clocked'’him, but this he did not regard as a crime.
1940		C. Allen in Dly News (Perth) 25 Sept. 6/4: I didn't mind him calling Churchill an old fogey, and I said nothing when he called Chamberlain a doddering old fool, but — blimey — when it comes to spitting in our ocean I had to clock him one!!
1941		Baker Popular Dict. Aus. Sl. 18: To clock, to strike with the fist.
1947		D. Davin For the Rest of Our Lives 51: So then I clocked him and we beat it up the sharia before the M.P.’s came.
1955		D. Niland Shiralee 122: She clocks him with a fryin’ pan or something.
1965		J.P. Carstairs Concrete Kimono 80: The players are liable to clock the ref., I’m told. Throw bottles.
1977		(con. 1940s) O. Manning Danger Tree 17: You pay me or me clock you.
1989		J. Hibberd Memoirs of an Old Bastard 111: She clocked me with a crutch.
1996		(con. 1946) G. Pelecanos Big Blowdown (1999) 69: Brown clocked the ref right in the kisser.
2005		K. Huff A Steady Rain I ii: I clocked him one square in the jaw with the top of my head.
2011		D. Telegraph 30 Apr. 28/1: Ed Balls said that if he addressed his wife in those terms she would ‘clock’ him.
2017		D. Remnick in New Yorker 18 Feb. 🌐 Trump resembled an over-sauced guy [...] facing three likely options in the near term: a) take a swing at someone, b) get clocked by someone else, or c) pass out.
2020		(con. 1991-94) W. Boyle City of Margins 18: There’s some blood showing in his hair. Donnie clocked him good.

4. (US) to reconnoitre, usu. of a possible crime site.

1950		Goldin et al. DAUL 45/2: Clock, v. To watch the movements of a prospective victim of crime, especially a watchman on his rounds.
1959		‘Screwsman’s Lament’ in Encounter n.d. in Norman Norman’s London (1969) 68: Kate gets out and clocks the drum, comes back and says it’s dead.
1972		B. Rodgers Queens’ Vernacular 47: clock (kwn SF, hip gay sl, fr underworld sl clockin’ = casing a joint; timing a victim’s daily routine) to scrutinize, size up.
1989		(con. 1950s–60s) in G. Tremlett Little Legs 38: We clocked the geezer and we could see that he was carrying money.
1992		in R. Graef Living Dangerously 50: You just clock doors that are open, windows, cars, car stereos.
1993		K. Scott Monster (1994) 57: Our ’hood was now being clocked by not just the Sixties but their allies and our new enemies.
2010		(con. 1973) C. Stella Johnny Porno 44: Louis had clocked him three consecutive Sundays [...] the collection route had been the same.
2017		1011 ‘No Hook’ 🎵 Clock me an opp wind down the window / Back out the spinner and burst him.

5. (US) of a prostitute, to pick up a customer.

1989

in N.Y. Mag. 11 Dec. 36: Getting customers is called ‘catchin’ or ‘clockin’.

6. to defeat, to beat.

2000

F.X. Toole Rope Burns 106: He got clocked in five by a 170-pound marine moonlighting out of Camp Pendleton. He quit again.