Gleeful chuckle (7)
I believe the answer is:
chortle
'gleeful chuckle' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for chortle that I've seen before include "Loud gleeful chuckle" , "Titter" , "Joyous chuckle" , "Laugh softly" , "Noisy gleeful laugh" .)