Present reasons for or against (5)
I believe the answer is:
argue
'present reasons for or against' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for argue that I've seen before include "Debate, contest verbally" , "Bandy words" , "Exchange heated views" , "Disagree violently" , "Debate, contend" .)