Green’s Dictionary of Slang

France n.

[the orig. use, France!, is as an oath, and refers to the horrors of WWI, when many West Indians fought and died in the trenches of Flanders. Thereafter, the uses can all be paralleled by fuck and/or hell, and usu. in phr. below. These uses may also have some background in the Du. Loop naar de Franschen, run to the French, i.e. go to the devil]

(W.I.) a euph. for fuck n. or hell.

In phrases

go to France (v.)

(US black) to receive oral sex.

[US]Trixie Smith ‘He Likes It Slow’ 🎵 Lord he likes it slow when he goes to dance, / He likes it slow when he goes to France.

In exclamations