Prince taking on monster to get further (8)
I believe the answer is:
progress
'get further' is the definition.
'prince taking on monster' is the wordplay.
'prince' becomes 'pr'.
'taking on' means one lot of letters go next to another.
'monster' becomes 'ogress' (I've seen this before).
'pr'+'ogress'='PROGRESS'
'to' acts as a link.
(Other definitions for progress that I've seen before include "Gradual improvement or development" , "Headway" , "Relating to verse" , "Get on with" , "Course" .)