Green’s Dictionary of Slang

1. (US) to eat.

1848

Ladies’ Repository (N.Y.) Oct. VIII:37 317/1: Souse, to eat.

2. (US) to hit.

1905

F. Hutchison Philosophy of Johnny the Gent 45: ‘[H]is main comedy stunt was to make a cuspidor out of his pal's eye and souse him in the puss wit’ the newspaper’.

3. to drink heavily, to become drunk; also as souse oneself.

1913		J. London Valley of the Moon (1914) 322: Old Susan liked John Barleycorn. She’d souse herself to the ears every chance she got.
1920		A. Baer Two & Three 6 Mar. [synd. col.] Aztecs didn’t souse and could run 100 miles in a day.
1935		G. Ingram Cockney Cavalcade 143: He’s soused himself till he’s no good.
1958		Kerouac letter 13 Apr. in Charters II (1999) 120: I don’t souse anymore, just a few cocktails for dinner, because I was really going Bowery way for a while there.
1989		Kirk & Madsen After The Ball 131: While sousing with the boys at the local bar.
1990		(ref. to 1943) A. Bérubé Coming Out Under Fire 103: He found his own clique of eight gay GIs who gathered ‘several times a week in one of the local ‘souse huts’.