A brute keeping right alongside (7)
I believe the answer is:
abreast
'alongside' is the definition.
(thesaurus)
'a brute keeping right' is the wordplay.
'brute' becomes 'beast' ('beast' can be a synonym of 'brute'**).
'keeping' means one lot of letters goes inside another.
'right' becomes 'r' (common abbreviation).
'beast' going around 'r' is 'breast'.
'a'+'breast'='ABREAST'
(Other definitions for abreast that I've seen before include "acquainted" , "Well-informed" , "Side by side - in the picture" , "Familiar" , "to be up to date" .)