Word processor using right IT to fill in answer? Not half (6)
I believe the answer is:
writer
'word processor' is the definition.
(someone who works with words)
'right it to fill in answer? not half' is the wordplay.
'right' becomes 'r' (common abbreviation).
'to fill in' means one lot of letters goes inside another.
'not half' suggests halving the letters.
'r'+'it'='rit'
'answer' halved is 'wer'.
'rit' placed into 'wer' is 'WRITER'.
'using' acts as a link.
(Other definitions for writer that I've seen before include "Novelist" , "See 1, 12, 15, 23 across and 3, 6, 9 down" , "Author; correspondent" , "See 4" , "Pope, for example" .)