acetabulum

noun7

1. •
   The bony cup of the hip bone which receives the head of the femur.
2. •
   The cavity in which the leg of an insect is inserted at its articulation with the body.
3. •
   A sucker of the sepia or cuttlefish and related animals.
4. •
   The large posterior sucker of the leeches.
5. •
   A vinegar saucer, especially (historical) in ancient Roman contexts.
6. •
   (historical) A Roman unit of liquid measure reckoned as the volume of 2½ Roman ounces of wine and equivalent to about 66 mL although differing slightly over time.
7. •
   One of the lobes of the placenta in ruminating animals.