back up

• POS: Verb (usu participle), Noun Phrase, Verb (intransitive)

CIDE DICTIONARY

back up, v. i. 

•  to move in a reverse direction; -- used of vehicles or animals.  [PJC]
•  to accumulate due to a blockage of flow; as, a traffic backup due to an accident; a sewage backup.  [PJC]

back up, v. t. 

•  to serve as a backup{3} for (another person or persons); as, the patrolmen backed up the detectives as they went inside to make the arrest; the center fielder backed up the shortstop on the play.  [PJC]
•  to make a backup{5} of; as, the sysop backed up the purchasing data files every night.  [PJC]

THESAURUS

back up

act for, advance, affirm, afford support, answer for, appear for, ascend, attest, authenticate, back, back away, back off, backpedal, backtrack, backtrail, backwater, bear, bear out, bear up, bolster, bolster up, brace, budge, buoy up, buttress, carry, certify, champion, change, change place, circle, circumstantiate, climb, come after, come last, commission, confirm, corroborate, countermarch, cradle, crutch, cushion, deputize, descend, document, ebb, elect, endorse, fall astern, fall back, fall behind, flow, follow, fortify, front for, get behind, get in behind, get over, give support, go, go around, go back, go backwards, go into reverse, go round, go sideways, gyrate, hold, hold up, keep afloat, keep up, lag behind, lend support, mainstay, maintain, make sternway, mount, move, move over, nominate, pillow, pinch-hit for, plunge, probate, progress, prop, prove, ratify, regress, reinforce, represent, retrogress, reverse, revert, rise, rotate, run, run interference for, second, shift, shore, shore up, shoulder, side with, sink, soar, speak for, spin, stand back of, stand behind, stand by, stand in for, stay, stick by, stick up for, stir, stream, strengthen, subside, subsidize, substantiate, substitute for, subvention, support, sustain, take sides with, trail, trail behind, travel, underbrace, undergird, underlie, underpin, underset, understudy, upbear, uphold, upkeep, validate, verify, vote, wane, warrant, whirl

ROGET THESAURUS

back up

Aid

VB aid, assist, help, succor, lend one's aid, come to the aid, of, contribute, subscribe to, bring aid, give aid, furnish aid, afford aid, supply aid, give a helping hand, stretch a hand, lend a helping hand, lend a hand, bear a helping hand, hold out a hand, hold out a helping hand, give one a life, give one a cast, give one a turn, take by the hand, take in tow, help a lame dog over a stile, lend wings to, relieve, rescue, set up, set agoing, set on one's legs, bear through, pull through, give new life to, be the making of, reinforce, reenforce, recruit, set forward, put forward, push forward, give a lift, give a shove, give an impulse to, promote, further, forward, advance expedite, speed, quicken, hasten, support, sustain, uphold, prop, hold up, bolster, cradle, nourish, nurture, nurse, dry nurse, suckle, put out to nurse, manure, cultivate, force, foster, cherish, foment, feed the flame, fan the flame, serve, do service to, tender to, pander to, administer to, subminister to, minister to, tend, attend, wait on, take care of, entertain, smooth the bed of death, oblige, accommodate, consult the wishes of, humor, cheer, encourage, second, stand by, back, back up, pay the piper, abet, work for, make interest for, stick up for, take up the cudgels for, take up the cause of, espouse the cause of, adopt the cause of, advocate, beat up for recruits, press into the service, squire, give moral support to, keep in countenance, countenance, patronize, lend oneself to, lend one's countenance to, smile upon, shine upon, favor, befriend, take in hand, enlist under the banners of, side with, be of use to, subserve, benefit, render a service, conduce.

Support

VB be supported, lie on, sit on, recline on, lean on, loll on, rest on, stand on, step on, repose on, abut on, bear on, be based on, have at one's back, bestride, bestraddle, support, bear, carry, hold, sustain, shoulder, hold up, back up, bolster up, shore up, uphold, upbear, prop, under prop, under pin, under set, riprap, bandage, give support, furnish support, afford support, supply support, lend support, give foundations, furnish foundations, afford foundations, supply foundations, lend foundations, bottom, found, base, ground, imbed, embed, maintain, keep on foot, aid.