American alongside bottom row (6)
I believe the answer is:
rumpus
'row' is the definition.
(both can mean a controversy or dispute)
'american alongside bottom' is the wordplay.
'american' becomes 'us' (abbreviation for United States).
'alongside' is a charade indicator (letters next to each other).
'bottom' becomes 'rump' (rump can informally mean someone's bottom).
'us' after 'rump' is 'RUMPUS'.
(Other definitions for rumpus that I've seen before include "Noisy, disruptive commotion" , "Kerfuffle" , "Noisy disturbance" , "Uproar or angry dispute" , "Making a fuss" .)