atrium
Pronunciation:
/ˈeɪ.tɹi.əm/noun
Definitions
A central room or space in ancient Roman homes, open to the sky in the middle; a similar space in other buildings.
A square hall lit by daylight from above, into which rooms open at one or more levels.
A cavity, entrance, or passage.
Any enclosed sexine and nexine layers, widening toward the interior of the grain.