Be beside (4)
I believe the answer is:
abut
'be beside' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for abut that I've seen before include "Adjoin, border" , "Adjoin, be contiguous to" , "Be next to -- share a boundary" , "Adjoin -- 19 (rev)" , "Adjoin, press up against" .)