Wiktionary
vb. (en-pastback up)
WordNet
adj. having backing; "a claim backed up by strong evidence" [syn: backed]
Usage examples of "backed up".
Billingsley backed up a step, looking nervously from the barechested cop to Steve.
He backed up and fell, and I don't remember what happened next but I think I took him then and there, because later I found the dagger still in his neck.
I cut his knife hand and scored his neck in two quick movements of the wrist that would have made my grandfather proud, then backed up a few steps.
They released her on the bottom step, backed up, bowed to her once, turned together, and walked up again without a backward glance.
But Wayvern recognized him at the same time, so the Saint stopped his driver, and the two cars slowed down a few yards past each other and backed up until they could talk.