Caught in squall, egret toppled pretty quickly (10)
I believe the answer is:
allegretto
'pretty quickly' is the definition.
(musical direction)
'caught in squall egret toppled' is the wordplay.
'caught in' indicates a hidden word.
'ALLEGRETTO' is hidden in the letters of 'squall egret toppled'.
(Other definitions for allegretto that I've seen before include "with reasonable rapidity" , "fairly speedily" , "Moving fairly briskly (music)" , "somewhat quick" , "at a fairly brisk rate" .)