Quickly getting stuck? (4)
I believe the answer is:
fast
I believe this clue is a double definition.
'quickly' is the first definition.
(I know that quickly can be written as fast)
'stuck' is the second definition.
(both can mean secure)
'getting' acts as a link.
(Other definitions for fast that I've seen before include "Period without food" , "Rapidly; tight" , "Quick - don't eat" , "Maybe bound to spot" , "Firm < moving rapidly" .)