Gutless swine about to plagiarise writer (6)
I believe the answer is:
scribe
'writer' is the definition.
(scribe is a kind of writer)
'gutless swine about to plagiarise' is the wordplay.
'gutless' means to remove the middle letters.
'about' is an insertion indicator.
'to plagiarise' becomes 'crib' (cribbing is a kind of plagiarising).
'swine' with its centre taken out is 'se'.
'se' placed around 'crib' is 'SCRIBE'.
(Other definitions for scribe that I've seen before include "Mark with a sharp point" , "One writing documents" , "Former document copier" , "Letter-writer of old" , "Medieval clerk" .)