Green’s Dictionary of Slang

squeak n.

[squeak v.]

1. (also squeek) an informer, esp. one who turns informer to save themselves after being arrested.

[UK]H.T. Potter New Dict. Cant (1795) n.p.: Squeak, a thief, who when taken up confesses and impeaches the rest of his companions.
[UK]G. Andrewes Dict. Sl. and Cant.
[UK]Flash Dict.
[US]‘Hal Ellson’ Tomboy (1952) 174: I happen to know you’re a goddam squeak.
[US]H. Ellison ‘Johnny Slice’s Stoolie’ in Deadly Streets (1983) 81: We hadn’t pulled anything [...] for fear the squeek would blow to the bulls.
[UK]J.J. Connolly Layer Cake 51: He’s always had a streak of the squeak in him.

2. a piece of information passed over to the police.

[Aus]Australian (Sydney) 13 Feb. 3/4: [N]othing, in fact, being a surer sign of want of true game, than raising a squeak about any theft whatever.
[Ire]Joyce Ulysses 469: The squeak is out. A split is gone for the flatties.
[UK]V. Davis Gentlemen of the Broad Arrows 165: Just at present there is a ‘squeak’; we’ve lost thirty-five quid in notes.
[UK]V. Davis Phenomena in Crime 94: A ‘squeak’ respecting the ‘czars’ of the dope racket.
[UK]P. Hoskins No Hiding Place! 192/2: The Squeak is Out. The police have information.
[UK](con. c.1910) A. Harding in Samuel East End Und. 82: The squeak came from a shopkeeper.

3. (Aus.) an escape.

[Aus]Crowe Aus. Sl. Dict. 80: Squeak, [...] an escape.

4. (US) a remark, a comment.

[US]T. Thursday ‘Words & Music’ in Top-Notch 15 June 🌐 When a girl has to measure out ribbons all day at Flooker’s Department Store she hasn’t got any time to delve into the squeaks of song writers.

5. (US police) a complaint.

[US]N.Y. Times 15 Dec. SM16: Squeak: complaint.

6. (US) a singer.

[US]J. Havoc Early Havoc 16: ‘We got enough squeaks dancing right out there in the contest [...] Ain’t it great that poor little bastard can still squeak out a song’.

In phrases

no squeaks

(UK Und.) no complaints.

[UK]Swell’s Night Guide 40: Madame (that is to say, the bawd-mistress-general), are [sic] downy donnas, and tumble a few, and no squeaks.
put the squeak in (v.) (also put in the squeak)

to betray to the authorities.

[US](con. 1910s) D. Mackenzie Hell’s Kitchen 84: The crooks used to wonder how the ‘D’s’ (detectives) got their information, and who was ‘putting in the squeak’ (supplying information).
[UK]Thieves Slang ms list from District Police Training Centre, Ryton-on-Dunsmore, Warwicks 8: Putting in the squeak: Informing the Police.
[UK]F.D. Sharpe Sharpe of the Flying Squad 252: I [...] came back to town to find out who had put the squeak in.
[UK]‘Henry Green’ Caught (2001) 74: Most likely someone put the squeak in, told them.
[UK]P. Hoskins No Hiding Place! 191/2: Put in the Squeak. Inform .
[UK](con. WW2) R. Poole London E1 (2012) 236: ‘Suppose someone put the squeak in to the Law’.

SE in slang uses

In compounds