acetabulum

‖n. [ L., a little saucer for vinegar, fr. acetum vinegar, fr. acere to be sour. ] [ 1913 Webster ]

1. (Rom. Antiq.) A vinegar cup; socket of the hip bone; a measure of about one eighth of a pint, etc. [ 1913 Webster ]

2. (Anat.) (a) The bony cup which receives the head of the thigh bone. (b) The cavity in which the leg of an insect is inserted at its articulation with the body. (c) A sucker of the sepia or cuttlefish and related animals. (d) The large posterior sucker of the leeches. (e) One of the lobes of the placenta in ruminating animals. [ 1913 Webster ]