Cancel the order for a girl to turn left (5)
I believe the answer is:
annul
'cancel the order' is the definition.
'annul' can be an answer for 'cancel' (annulling is a kind of cancelling). I'm not certain of the 'the order' bit.
'a girl to turn left' is the wordplay.
'a girl' becomes 'ann' (woman's name).
'to turn' becomes 'u' (a 'U-turn' is a kind of turn).
'left' becomes 'l' (common abbreviation).
'ann'+'u'+'l'='ANNUL'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for annul that I've seen before include "Cancel, abolish" , "Declare (a law) invalid" , "Render invalid" , "Cancel or render void" , "Repeal, rescind" .)