Strike, touch careless (8)
I believe the answer is:
slapdash
'careless' is the definition.
(similar in meaning)
'strike touch' is the wordplay.
'strike' becomes 'slap' (slapping is a kind of striking).
'touch' becomes 'dash' (I have seen 'A touch' mean 'dash' so perhaps 'touch' could also mean 'dash').
'slap'+'dash'='SLAPDASH'
(Other definitions for slapdash that I've seen before include "Perfunctory" , "Slipshod, sloppy" , "Hasty and careless - hit and run?" , "Quick, careless" , "Careless - haphazard" .)