A diversion meant for playing outside, you think (9)
I believe the answer is:
amusement
'a diversion' is the definition.
(amusement is a kind of diversion)
'meant for playing outside you think' is the wordplay.
'for playing' is an anagram indicator.
'outside' means one lot of letters goes inside another (some letters go outside others).
'you think' becomes 'muse' (I can't justify this - if you can you should believe this answer much more).
'meant' with letters rearranged gives 'ament'.
'ament' going around 'muse' is 'AMUSEMENT'.
Can you help me to learn more?
(Other definitions for amusement that I've seen before include "Pleasure, diversion" , "Idle wasting of time" , "Diversion, recreation" , "Pleasant diversion by mute means (9)" , "Something which entertains" .)