Dry period quickly over (3)
I believe the answer is:
sec
I believe this clue is a double definition.
'dry' is the first definition.
('sec' can be similar in meaning to 'dry')
'period quickly over' is the second definition.
(Other definitions for sec that I've seen before include "21 down, as wine" , "Mo or min?" , "sparkling?" , "Jiffy" , "'Dry, as wine (3)'" .)