Longest sentence in Gogol, if extended (4)
I believe the answer is:
life
'longest sentence' is the definition.
(I've seen this before)
'in gogol if extended' is the wordplay.
'in' says the answer is hidden in the clue.
'LIFE' is hidden in the letters of 'gogol if extended'.
(Other definitions for life that I've seen before include "Actuarial estimate of our remaining years" , "and 12 Down: Biology, medicine, etc" , "Vitality, vigour" , "'While there's .... there's hope'" , "Birth to death" .)