A replacement, especially a tire, reserved for future need.
A person or thing that can always be depended on, is always effective, etc.
The definition of supplementary is something that is added on, or that completes something.
(computer science) a copy of a file or directory on a separate storage device
(Grammar) A word or construction used in place of another word, phrase, or clause.
For use during emergencies:
The definition of an understudy is an actor who learns the role of another actor and who performs when that actor is unable.
The power to appoint to office or grant other favors, esp. political ones
The definition of an accompaniment is an item that goes with something else, or a musical part intended to be played in support of the other parts of the piece.
a musical part (vocal or instrumental) that supports or provides background for other musical parts
Financial or other help.
Additional personnel or equipment sent to support a military action.
A reservation of public land:
One that helps:
A second helping of something to eat
(Not comparable) Not current.
The definition of back up means someone or something that is a substitute or reinforcement.
Possessing some quality, or having been subject to some operation (as substitution), in the second degree; as, a secondary salt, a secondary amine, etc. Compare primary.
Used or held in reserve
Support or aid:
The group of players that substitute for the starting players or from which substitute players are drawn on a sports team.
Relief is the ease of pain, tension, strain or other discomfort.
(Baseball) A relief pitcher.
someone who takes the place of another (as when things get dangerous or difficult)
One that serves as a substitute for another.
Find another word for backup. In this page you can discover 43 synonyms, antonyms, idiomatic expressions, and related words for backup, like: spare, standby, supplementary, computer backup, substitute, emergency, championship, supporting, understudy, supplemental and patronage.