1857. Snowden, Magistrates’ Assistant, 3rd ed., p. 446. A policeman; a fly.
Adj. (common).—1. Knowing; artful (q.v.); up to every move; cute. Also fly to, a-fly, fly to the game, and fly to what’s what. Cf., Awake, and, for synonyms, see Knowing; fly dog (q.v.).
1811. Lexicon Balatronicum, Cheese it, the coves are fly = be silent, the people understand our discourse.
1823. W. T. Moncrieff, Tom and Jerry, Act II., Sc. 2. Jerry. Charlies’ fiddles?—I’m not fly, Doctor. Log. Rattles, Jerry, rattles! Jerry rattles! you’re fly now, I see.
1838. Glascock, Land Sharks and Sea Gulls, II., 4. That’s right; I see you’re fly to every fakement.
1850. Lloyd’s Weekly, 3 Feb. ‘Low Lodging Houses of London.’ They say the fliest is easy to take in sometimes—that’s the artfullest; but I could do no good there.
1851–61. H. Mayhew, Lond. Lab. and Lond. Poor, vol. I., p. 260. ‘We were too fly to send anybody to market but ourselves.’
1861. H. Kingsley, Ravenshoe, ch. xxxv. [Chas. Ravenshoe to Shoeblack]. ‘On the cross?’ said Charles. ‘Ah,’ the boy said, ‘he goes out cly-faking and such. He’s a prig, and a smart one, too. He’s fly, is Harry.’
1876. Miss Braddon, Dead Men’s Shoes, ch. lii. ‘Go and fetch the cleverest police officer in Liverpool, and let him wait outside this door till I want him.’ ‘I’m fly,’ answers the youth, brightening at the prospect of excitement and remuneration. ‘Case of ’bezzlement, I suppose, Sir?’
1877. Five Years’ Penal Servitude, ch. ii., p. 125. A certain prisoner, who was what is termed a very fly man, i.e., a clever, scheming fellow … sounded him as to getting tobacco and other matters.