Natural impulse in street and in court (8)
I believe the answer is:
instinct
'natural impulse' is the definition.
'in street and in court' is the wordplay.
'street' becomes 'st'.
'and' means one lot of letters go next to another.
'court' becomes 'ct'.
'in'+'st'+'in'+'ct'='INSTINCT'
(Other definitions for instinct that I've seen before include "Innate behavioural pattern" , "Inborn impulse or tendency 8)" , "Natural way of thinking" , "Nothing learned" , "Natural inclination" .)