Two chaps who’ll make you giggle? (2-2)
I believe the answer is:
he-he
'giggle?' is the definition.
(he-he is a giggling sound)
'two chaps' is the wordplay.
'two chaps' can mean two replacements for 'chap'.
'chap' becomes 'he'.
'chap' becomes 'he'.
'he'+'he'='HE-HE'
'who'll make you' acts as a link.
(Other definitions for he-he that I've seen before include "Sound of laughter" , "Amused expression" .)