Rag in original box round gym (9)
I believe the answer is:
newspaper
'rag' is the definition.
(rag can informally mean a newspaper)
'in original box round gym' is the wordplay.
'in' indicates putting letters inside.
'original' becomes 'new' (similar in meaning).
'box round' becomes 'spar' (spar can mean to box. I am not sure about the 'round' bit.).
'gym' becomes 'pe' (short for Physical Education).
'new'+'spar'='newspar'
'newspar' going around 'pe' is 'NEWSPAPER'.
Can you help me to learn more?
(Other definitions for newspaper that I've seen before include "Journal" , "printed edition" , "part of the media" , "Broadsheet, e.g." , "It's (mainly) black and white, and read all over!" .)