Possibly meant to think going in will create a diversion (9)
I believe the answer is:
amusement
'a diversion' is the definition.
(I know that amusement is a type of diversion)
'possibly meant to think going in' is the wordplay.
'possibly' indicates anagramming the letters.
'to think' becomes 'muse' (to muse on something is to think about it).
'going in' is an insertion indicator.
'meant' with letters rearranged gives 'ament'.
'ament' placed around 'muse' is 'AMUSEMENT'.
'will create' is the link.
(Other definitions for amusement that I've seen before include "Pastime; recreation" , "Something which entertains" , "Pleasant diversion by mute means (9)" , "(State of) finding something funny" , "Pleasure, diversion" .)