Amuse pedant coming out of his shell (6)
I believe the answer is:
tickle
'amuse' is the definition.
(I know this)
'pedant coming out of his shell' is the wordplay.
'pedant' becomes 'stickler' (a pedant is a stickler for detail).
'coming out of his shell' means to look at the middle letters (the outside letters or 'shell' are removed).
The central letters of 'stickler' are 'TICKLE'.
(Other definitions for tickle that I've seen before include "Excite by touch" , "Amuse; touch lightly" , "Cause to laugh by manual means" , "Touch lightly to cause laughter" , "Stimulate" .)