Green’s Dictionary of Slang

fixed bayonet n.

1. an erect penis.

[UK]Farmer & Henley Sl. and Its Analogues.

2. (Aus. milit.) red wine.

[Aus](con. WWI) A.G. Pretty Gloss. of Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: fixed bayonet. Vin Rogue [sic] (red wine).

3. (N.Z. milit., also fix bayonets) methylated spirits.

[NZ](con. WWII) McGill Dict. of Kiwi Sl. 45/1: fix bayonets methylated spirits; variant of military term for Bermuda rum, with ref. its sting; WWII.
[NZ]McGill Reed Dict. of N.Z. Sl. [as cit. 1988].