Finished half of this part of the golf course (7)
I believe the answer is:
through
'finished' is the definition.
(similar in meaning)
'half of this part of the golf course' is the wordplay.
'half of' suggests halving the letters.
'part of the golf course' becomes 'rough' ('rough' is part of 'golf course').
'this' with half the letters taken is 'th'.
'th'+'rough'='THROUGH'
(Other definitions for through that I've seen before include "Finished; by way of" , "having arrived at next stage" , "done" , "From one end or side to the other" , "No longer going out together" .)