Laugh when her colt bolts (7)
I believe the answer is:
chortle
'laugh' is the definition.
(chortling is a kind of laughing)
'her colt bolts' is the wordplay.
'her colt' can be anagrammed to 'CHORTLE'.
However, I'm not clear how this is indicated.
'when' is the link.
Can you help me to learn more?
(Other definitions for chortle that I've seen before include "Guffaw" , "Loud gleeful chuckle" , "Chuckle gleefully" , "Laugh out loud" , "Joyous chuckle" .)