backer-up

[ bak-er-uhp ]
/ ˈbæk ərˈʌp /

noun, plural back·ers-up.

a supporter; backer; second.
Football. a linebacker.

Origin of backer-up

1920–25; back up + -er1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019