In general, lecturers rejected underground room (6)
I believe the answer is:
cellar
'underground room' is the definition.
(I've seen this before)
'in general lecturers rejected' is the wordplay.
'in' indicates the answer is hidden within the clue.
'rejected' is a reversal indicator.
'rallec' is hidden in the letters of 'general lecturers'.
'rallec' backwards is 'CELLAR'.
(Other definitions for cellar that I've seen before include "Room where wine is stored (6)," , "Underground room - stock of bottled wines" , "Bottom room where wine is often stored" , "Storage space below ground" , "Room below ground for storage" .)