Not quite all slip home (4)
I believe the answer is:
gaff
'home' is the definition.
(I've seen this before)
'not quite all slip' is the wordplay.
'not quite all' means to remove the last letter (most but not all of the word is used).
'slip' becomes 'gaffe' (both can mean an error or blunder).
'gaffe' with its last letter taken away is 'GAFF'.
(Other definitions for gaff that I've seen before include "Fishing spear" , "one's home" , "Angler's pole - it can be blown" , "Pole with hook used by anglers" , "Fisherman's stick with iron hook" .)