Quickly I recollect Athens (2,5)
I believe the answer is:
in haste
'quickly' is the definition.
(I've seen this before)
'i recollect athens' is the wordplay.
'recollect' is an anagram indicator.
'athens' is an anagram of 'nhaste'.
'i'+'nhaste'='IN HASTE'
(Other definitions for in haste that I've seen before include "Rashly (how not to marry?)" , "Rapidly" , "Quickly" , "Hurriedly" , "''Marry . . . . . . ., repent at leisure'' (2, 5)" .)