noun, masculine/feminine/lɛʃ.ky/plural: lèche-cul
ass-licker (US), arse-licker (UK)
Synonyms: lèche-bottes, cire-pompes
From lécher (“to lick”) + cul (“arse, hole”). Said because the ass is considered vulgar and being willing to kiss another's is considered a sign of submission and patronage.