Green’s Dictionary of Slang

up against phr.

1. [late 19C+] (orig. US) facing problems, in difficulties; esp. in phr. up against it.

2. [late 19C+] (US prison) addicted to drugs.

3. [1900s] the responsibility of.

In phrases

go up against (v.)

1. (US drugs) to smoke opium as an addict (rather than an occasional user).

2. (US Und.) to attempt a robbery.

up against one’s duckhouse (also’s fowlhouse, one for one’s duckhouse roof)

[1930s+] (Aus.) denoting a setback, a problem; usu. in phr. that’s one up against your duckhouse.

up against the stem [stem n.]

[1970s+] (drugs) addicted to smoking marijuana.

up against the wall [the putting of prisoners against a wall to face a firing squad] (orig. milit.)

1. [1910s+] (also ...the bit, …the bricks, ...the gun, ...the push, ...the ropes, ...the wire) facing serious problems.

2. [1960s+] (US campus) foolish, stupid [reinforced by 1960s’ radical slogan, Up against the wall, motherfucker!].