"lol" (2-2)
'lol' is the definition.
(I know that lol can be written as haha)
This is the entire clue.
(Other definitions for haha that I've seen before include "Laugh" , "The sound of laughter" , "Ditch" .)
(Other definitions for he-he that I've seen before include "Sound of laughter" , "Amused expression" .)