Green’s Dictionary of Slang

1. (UK tramp) money acquired through begging, or trickery; also as v.

1923

M. Garahan Stiffs 230: I sure did have a wonderful click at Margate. [Ibid.] 298: Kip and grub on the scale of the last year were secure for many months. For years I could live the life of a stiff who has clicked.

2. the making of an acquaintance; a flirtation, a pick-up.

1923		Eve. Teleg. (Dundee) 16 Oct. 5: The average office boy’s talk of a morning after a previous evening’ attendance [...] generally savours of the ‘clicks’ he has made.
1936		K. Mackenzie Living Rough 170: She talked more about clicks, jigging, and pictures.
1941		V. Davis Phenomena in Crime 79: Following up the ‘click’ with a flood of feminine charm.

3. (US, also clicker) a success [appears orig. to have been a Winchellism].

1938		H.M. Anderson Strip Tease 15: ‘The tease must have been a click the first time out’.
1942		W. Winchell On Broadway 17 Mar. [synd. col.] Ben Oakland’s ditty: ‘The Flag’s Still There, Mr Key’ — a clicker.
1943		W. Winchell On Broadway 2 May [synd. col.] Talk about quick clicks on Broadway.
1943		R.L. Bellem ‘Feature Snatch!’ Dan Turner - Hollywood Detective Feb. 🌐 It [i.e. a movie] turned out to be a click all over the country.
1952		W. Winchell ‘On Broadway’ 18 Aug. [synd. col.] His wham click at the Capri is Main Stem gab.
1960		D. Lytton Goddam White Man 136: We made a click hey, when you try to put a lock on me. We made a good click there.

4. see klick n.