acetabulum /a-si-tabˈū-ləm or -sē-/ (zoology)

1. The hollow that receives the head of the thigh bone
2. One of the cotyledons of the placenta of ruminants
3. The cavity that receives a leg in the body of insects
4. (in various invertebrates) a sucker

acetabˈūlar adjective

• twin paradox
• twin paradoxes
• twin plane
• twin planes
• twins
• twin-screw
• twinset
• twinsets
• twinship
• twinships
• twin sister
• twin sisters
• twinter
• twinters
• twin town
• twin towns
• twin-track
• twin-tub
• twin-tubs
• twiny
• twire
• twired
• twires
• twiring
• twirl