Cut down boy's free time outside (7)
I believe the answer is:
abridge
'cut down' is the definition.
(I've seen this in another clue)
'boy's free time outside' is the wordplay.
'boy' becomes 'b' (abbreviation used in schools).
'free' becomes 'rid' (to be free of something is to be rid of it).
'time' becomes 'age' (an age is a period of time).
'outside' is an insertion indicator.
'b'+'rid'='brid'
'brid' going into 'age' is 'ABRIDGE'.
(Other definitions for abridge that I've seen before include "Crop" , "Cut short" , "trim" , "Big read (anag) - shorten text" , "Shorten (eg, text)" .)