Being tickled made us mad! (6)
I believe the answer is:
amused
'being tickled' is the definition.
(I've seen this before)
'made us mad' is the wordplay.
'mad' is an anagram indicator.
'made'+'us'='madeus'
'madeus' with letters rearranged gives 'AMUSED'.
(Other definitions for amused that I've seen before include "Mildly entertained by Medusa" , "Queen Victoria wasn't!" , "Kept someone entertained" , "Pleasantly occupied" , "Made (someone) laugh" .)