[ ˌasɪ'tabjʊləm ]
■ noun ( plural acetabula -lə )
1》 Anatomy the socket of the hip bone, into which the head of the femur fits.
2》 Zoology a sucker or other cup-shaped structure.
Origin
ME (denoting a vinegar cup): from L., from acetum 'vinegar' + -abulum , denoting a container.