Have a bearing on (6)
I believe the answer is:
affect
'have a bearing on' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for affect that I've seen before include "impress" , "Make a difference to" , "Have impact on or arouse sadness in" , "Make impression on or arouse sympathy in" , "Have repercussions on" .)