wounded soldier, n. — Green’s Dictionary of Slang

wounded soldier n.

[play on dead soldier under soldier n., which is completely empty]

(US campus) a partially empty beer container.

1991		Eble Campus Sl. Fall.
1996		Eble Sl. and Sociability 31: Dead soldier is a metaphor for ‘empty beer container’ and wounded soldier for ‘a partially emptied’ one.