antrum
noun
an·trum ˈan-trəm 
plural antra ˈan-trə
: an anatomical cavity within a bone (such as the maxilla) or hollow organ (such as the stomach)
antral
ˈan-trəl
adjective 
Word History
Etymology
Late Latin, from Latin, cave, from Greek antron; akin to Armenian ayr cave
First Known Use
1684, in the meaning defined above
Medical Definition
antrum
noun
an·trum ˈan-trəm
plural antra -trə
: a cavity within a bone (as the maxilla) or hollow organ (as the stomach)
- out in the open
- out into the open
- out island
- Out Islands
- out like a light
- out loud
- out of
- out of action
- out of alignment
- out of breath
- out of business
- out of central casting
- out of character
- out of choice
- out of circulation
- out of commission
- out of condition
- out of contention for
- out of court
- out of danger
- out of earshot
- out of fashion
- out of favor
- out of focus
- out of hand