Inattentive pedestrian perhaps crosses end of avenue (8)
I believe the answer is:
careless
'inattentive' is the definition.
(associated in meaning)
'pedestrian perhaps crosses end of avenue' is the wordplay.
'pedestrian perhaps' becomes 'carless' (a pedestrianised area is an area without cars).
'crosses' indicates putting letters inside.
'end of' indicates one should take the final letters.
The final letter of 'avenue' is 'e'.
'carless' enclosing 'e' is 'CARELESS'.
(Other definitions for careless that I've seen before include "Lackadaisical" , "impetuous" , "Unconcerned, heedless" , "Incautious" , "Slapdash" .)