About to cut off 50 voting (4)
I believe the answer is:
poll
'voting' is the definition.
(I've seen this in other clues)
'about to cut off 50' is the wordplay.
'about' shows that the letters should be reversed in order.
'to cut off' becomes 'lop' (I've seen this in another clue).
'50' becomes 'l' (Roman numeral).
'lop' in reverse letter order is 'pol'.
'pol'+'l'='POLL'
(Other definitions for poll that I've seen before include "Voting process; parrot" , "Take away" , "straw, for example" , "Ballot" , "Head; register of voters" .)