Acetabulum

Part of speech: noun (n.)

1. A vinegar cup; socket of the hip bone; a measure of about one eighth of a pint, etc.

2. The bony cup which receives the head of the thigh bone.

3. The cavity in which the leg of an insect is inserted at its articulation with the body.

4. A sucker of the sepia or cuttlefish and related animals.

5. The large posterior sucker of the leeches.

6. One of the lobes of the placenta in ruminating animals.