Being rewritten in part and increased in size (4)
I believe the answer is:
grew
'increased in size' is the definition.
(I've seen this before)
'being rewritten in part' is the wordplay.
'in part' indicates the answer is hidden within the clue.
'GREW' is hidden in the letters of 'being rewritten'.
'and' is the link.
(Other definitions for grew that I've seen before include "Got larger" , "Expanded - flourished" , "Increased in size" , "Sprouted" , "Became larger" .)