Green’s Dictionary of Slang

airedale n.

also airdale
[horseracing jargon airedale, a worthless racehorse; note Wilstach (1924): ‘Leo Donnelly had his foot stepped on by a Jew on 42nd St. and said, “Hey there, you airdale.” Asked why he called him an airdale he said: “he was hairy, dirty and cute.”’]

1. [1920s] (US) an unattractive man.

2. [1920s] (US) a racing horse.

3. [1920s–40s] (US) a fool, a worthless person, a pest.

4. [1930s] (US Und.) a trustworthy friend.

5. [1930s–40s] (US Und.) a guard or watchman.

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

7. [1940s] (US Und.) one who runs errands for bootleggers or drug sellers.