Put tiny boy in gym for break (8)
I believe the answer is:
playtime
'for break' is the definition.
(I've seen this before)
'put tiny boy in gym' is the wordplay.
'put' becomes 'lay' (as in laying or putting something down).
'tiny boy' becomes 'Tim' (A Christmas Carol character Tiny Tim).
'in' indicates putting letters inside.
'gym' becomes 'pe' (short for Physical Education).
'lay'+'tim'='laytim'
'laytim' put into 'pe' is 'PLAYTIME'.
(Other definitions for playtime that I've seen before include "Recreation period" , "Curtain up" , "Schoolchildren's break" , "Period for pleasure" , "Break in school day" .)