Green’s Dictionary of Slang

scat n.¹

(US Und.) whisky, esp. of poor quality.

1909		implied in scat joint
1914		Jackson & Hellyer Vocab. Criminal Sl. 73: Scat [...] Whiskey. Derived by suggestion from ‘skey’ (skee), the termination of ‘whiskey’.
1919		St Louis Post-Despatch 16 Jan. 25/2: The trouble with you is [...] you’re slopping up too much scat (whiskey).
1929		A.J. Barr Let Tomorrow Come 44: You get a hideful o’ scat once in a while.
1940		D. Maurer Big Con 306: scat. Whisky.
1950		Goldin et al. DAUL 185/1: Scat. Whiskey, especially of the cheapest grade.

In compounds

scat joint (n.)

(US Und.) a bar.

1909

F.H. Tillotson How I Became a Detective 95: Scat joint – A saloon.