Cathys out to get a bloke - a sailor (9)
I believe the answer is:
yachtsman
'a sailor' is the definition.
(I know that sailor can be written as yachtsman)
'cathys out to get a bloke' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'to get' says to put letters next to each other.
'a bloke' becomes 'man' (informal term for a man).
'cathys' with letters rearranged gives 'yachts'.
'yachts'+'man'='YACHTSMAN'
(Other definitions for yachtsman that I've seen before include "crafty person" , "Description of Chichester" , "Sir Francis Chichester, perhaps" , "I may go round the world" , "sportsperson involved with rigging?" .)