Present reduction is wrong (9)
I believe the answer is:
introduce
'present' is the definition.
(I know that present can be written as introduce)
'reduction is wrong' is the wordplay.
'is wrong' indicates an anagram.
'reduction' is an anagram of 'INTRODUCE'.
(Other definitions for introduce that I've seen before include "To add" , "Bring in - cause to meet" , "Make one person known to another" , "Do the honours" , "Bring into practice - reduction (anag)" .)