borrowed from Latin acētābulum "small cup (originally used for vinegar), sucker of a polyp, socket of the hip bone," from acētum "vinegar" + -a- (by analogy with derivatives formed from verbs, as vocābulum vocable) + -bulum, instrument suffix (going back to Indo-European *-dhlom) — more at acetic acid

Note: Late Indo-European apparently possessed several deverbal instrumental suffixes of similar shape (*-dhlo-, *-tlo-, *-dhro-, *-tro-, perhaps all originally < *-tro-, zero-grade of the agent suffix -tor), which are unevenly attested and partially conflated in the daughter languages. Note in Latin rōstrum "beak, rostrum"; crībrum "sieve" (see cribriform); obstāculum obstacle; stabulum stable entry 1.