Class try unoccupied gym (4)
I believe the answer is:
type
'class' is the definition.
(both can mean a variety or kind)
'try unoccupied gym' is the wordplay.
'unoccupied' means to remove the middle letters (remove the inside letters which occupy the word).
'gym' becomes 'pe' (short for Physical Education).
'try' with its centre removed is 'ty'.
'ty'+'pe'='TYPE'
(Other definitions for type that I've seen before include "output, printed" , "Kind - press keys" , "Sort, kind" , "Class, kind or category" , "Produce characters" .)