Vie to hold left end (8)
I believe the answer is:
complete
'end' is the definition.
(completing is a kind of ending)
'vie to hold left' is the wordplay.
'vie' becomes 'compete' ('compete' can be a synonym of 'vie').
'to hold' is an insertion indicator.
'left' becomes 'l' (common abbreviation).
'compete' placed around 'l' is 'COMPLETE'.
(Other definitions for complete that I've seen before include "Whole and unabridged" , "Finished - whole" , "Whole, entire, uncut" , "Bring to a finish" , "Intact" .)