back up
noun(back-up)
one that serves as a substitute or support
back up
noun(back-up)
musical accompaniment
back up
noun(back-up)
additional personnel who provide assistance
back up
verb(back-up)
to accumulate in a congested state
back up
verb(back-up)
to move into a position behind (a teammate) in order to assist on a play
back up
verb(back-up)
hold back
back up
idiom(back-up)
to become angry or annoyed and want to fight or argue
back up
idiom(back-up)
to offend or annoy someone : to make someone angry or ready to argue