Green’s Dictionary of Slang

1. (US) an unattractive man.

1922		Edwardsville Intelligencer (lL) 14 Sept. 4/4: The Flappers’ Dictionary [...] Airdale: A Homely man.
1929		News-Chron. (Shippenberg, PA) 29 Oct. 4/3: Jack, the parlor leech crashed a party at Mary’s house. She’s some inkwell but before she got through with that airdale he sure was blotto .
1930		M. West Babe Gordon (1934) 28: ‘Listen, airedale,’ she said, ‘if I want you I’ll whistle for you.’.

2. (US) a racing horse.

1929

H.C. Witwer Yes Man’s Land 154: ‘I told you to lay off them airedales!’ he growls. ‘Cheez, anybody that gambols on horse races is about ready to cut out paper dolls.’.

3. (US) a fool, a worthless person, a pest.

1926		Maines & Grant Wise-crack Dict. 7/2: Don’t be an airdale – Rebuke for fickleness.
1933		W.R. Burnett Dark Hazard (1934) 61: Sit down, Turner [...] Don’t be an airedale. Sit down.
1950		Goldin et al. DAUL 17/2: Airedale. One who is fawningly loyal, as a dog to a master. ‘I ain’t playin’ the fall guy (one who takes sole blame) on this rap (charge). What do I look like, an airedale?’.

4. (US Und.) a trustworthy friend.

1933		Ersine Und. and Prison Sl.
1936		H. Corey Farewell, Mr Gangster! 276: Airedale – a dependable pal.

5. (US Und.) a guard or watchman; a policeman.

1931		‘Und. “Lingo” Brought Up-to-Date’ L.A. Times 8 Nov. K3: AIREDALE: A special guard.
1949		Monteleone Criminal Sl. (rev. edn).
1960		(con. 1950-1960) R.A. Freeman Dict. Inmate Sl. (Walla Walla, WA) 2: Airedale – a policeman, etc.

6. (US) usu. pl., a foot [play on dogs n.¹ (1)].

1940

J. Archibald ‘No Place Like Homicide’ in Popular Detective Apr. 🌐 With those airedales you could clean up stamping out grass fires.

7. (US Und.) one who runs errands for bootleggers or drug sellers.

1949

Monteleone Criminal Sl. (rev. edn).

8. (US prison) a go-between, a ‘fixer’.

1960

(con. 1950-1960) R.A. Freeman Dict. Inmate Sl. (Walla Walla, WA) 2: Airedale – a fixer; a mouthpiece.