Man, perhaps, I almost killed (4)
I believe the answer is:
isle
'man perhaps' is the definition.
(Isle of Man is an example)
'i almost killed' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'killed' becomes 'slew' (historical past tense of slay).
'slew' with its final letter taken off is 'sle'.
'i'+'sle'='ISLE'
(Other definitions for isle that I've seen before include "Capri for one" , "Fair one is in shipping bulletin" , "Spot (in ocean)" , "eg Man, Ely" , "Land encircled by water" .)