Bother, irritate (5)
I believe the answer is:
annoy
I believe this is a double definition.
'bother' is the first definition.
(I know that bother can be written as annoy)
'irritate' is the second definition.
(I know that irritate can be written as annoy)
(Other definitions for annoy that I've seen before include "Irk" , "Bug, rile" , "trouble" , "Anger" , "be a nuisance" .)