Personal computer apt to cut out? (6)
I believe the answer is:
laptop
'personal computer' is the definition.
(laptop is a kind of personal computer)
'apt to cut out?' is the wordplay.
'to cut' becomes 'lop' (lopping is a kind of cutting).
'out?' is an insertion indicator.
'apt' put within 'lop' is 'LAPTOP'.
(Other definitions for laptop that I've seen before include "Portable computer" , "Some work on this" , "Aid for businessman" , "device?" , "Kind of computer" .)