Careless chaps clearing verges put at risk (9)
I believe the answer is:
haphazard
'careless' is the definition.
(similar in meaning)
'chaps clearing verges put at risk' is the wordplay.
'clearing verges' means to look at the middle letters (letters at the edges or verges are removed).
'put at risk' becomes 'hazard' (synonyms).
The middle of 'chaps' is 'hap'.
'hap'+'hazard'='HAPHAZARD'
(Other definitions for haphazard that I've seen before include "Disorganised, random" , "Careless or random" , "Slapdash, slipshod" , "Erratic" , "Lacking any obvious organisation" .)