backup - noun

an accumulation caused by clogging or a stoppage

someone who takes the place of another (as when things get dangerous or difficult)

a musical part (vocal or instrumental) that supports or provides background for other musical parts

(computer science) a copy of a file or directory on a separate storage device

the act of providing approval and support

backup - thesaurus

accompaniment   backing   championship   patronage   relief   reliever   substitute   support