They may have glass ceilings (5)
I believe the answer is:
atria
'they may have glass ceilings' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for atria that I've seen before include "Central courts, halls" , "Lobbies" , "Open-roofed courts" , "Public spaces with galleries" , "Parts of the heart or of Roman houses" .)