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

Usage examples of backup.

Being from Bollywood, Sanjay never went anywhere in life without a posse of backup dancers.

I shake my traveling risers loose from my full-body harness, slide my hands over the crowded gear sling that we call a rack, find the two-bearing pulley by feel, clip it on to the riser ring with a carabiner, run a Munter hitch into a second carabiner as a friction-brake backup to the pulley brake, find my best offset-D carabiner and use it to clip the pulley flanges together around the cable, and then run my safety line through the first two carabiners while tying a short prusik sling onto the rope, finally clipping that on to my chest harness below the risers.

Furthermore, even if we wait three years, some of the older backup cores would be uninfected.

Norway was in the hands of the so-called South Varanger Garrison, with a reserve force, the Finnmark Brigade, to provide rapid backup in case of trouble.

George R should have messaged backup, confirmed availability, then let Hideo know he was off the hooka total of three keystrokes.

Lance bit back a smile as he watched a look of intense concentration cross her face as she put the bus in reverse, the backup warning chime beep-beep-beeping.

Hooker would be led by some of the Diaspran veterans, under the command of Krindi Fain, with the human Marinesled by Gunny Jinas emergency backup.

With formalities smoothed by the mention of Herbie Mossman, he had bought himself the usual Yasha 7 plus the backup of a nine millimeter automatic and, as an afterthought, a shoulder holster.

Pieces of the backup warp-drive were all over the floor, or hovering on placeholders, and Scotty was thundering around among his engineering ensigns, shouting at them.

Some researchers contended that memories of specific events were redundantly stored in several or lots of places in the network, or in a primary place with what amounted to backup.

She had wanted to sing backup for somebody like Bob Seger, but it was really hard getting a gig in this town.

Knowing the way such people operated, Samurai guessed that there would be a backup group here in Semipalatinsk as well.

The rule book call would be for her to radio for backup, since the man in the leather coat, Luther Slyke, was a predicate felon, known to be dangerous and more than likely heavily armed.

While I could subdue him with my superduper strength, I wanted some backup in case he whipped out a weapon of his own.

Jurgen noticed for the first time that Tipton had his backup pistol in his left hand.