Green’s Dictionary of Slang

sloppy adj.

[SE; ult. slop, an act of spilling, the liquid thus spilt]

1. [early 19C+] lazy, inefficient, imprecise.

2. [late 19C+] mawkishly sentimental.

3. [1910s+] (US) messy.

4. [1920s+] (US, also slip-sloppy) drunk.

In compounds

sloppy-ass (adj.)

[1950s] (US) overcome by drink.

In phrases

get sloppy (v.) [1980s+]

1. (US black/campus) to get drunk.

2. to have sexual intercourse.