THESAURUS
back down
abjure, back off, back out, backpedal, backtrack, backwater, balance, balk, beat a retreat, beg off, break off combat, cave in, cease resistance, climb down, crawfish out, cry off, debate, deliberate, demur, deny, disavow, disclaim, disengage, disown, draw back, draw off, eat crow, eat humble pie, fall back, falter, fear, forswear, give ground, give in, give place, give up, give way, go back, go back on, hang back, hem and haw, hesitate, hold back, hover, hum and haw, jib, move back, pause, ponder, pull back, pull out, quit the field, recall, recant, renege, renounce, repudiate, resile, retire, retract, retreat, revoke, run back, scruple, shilly-shally, shy, stand back, stick at, stickle, stop to consider, straddle the fence, strain at, swallow, take back, think twice about, unsay, weasel out, welsh, withdraw, yield
ROGET THESAURUS
back down
Regression
VB
recede, regrade, return, revert, retreat, retire, retrograde, retrocede, back out,
back down, balk, crawfish, crawl, withdraw, rebound, go back, come back, turn back, hark back, draw back, fall back, get back, put back, run back, lose ground, fall astern, drop astern, backwater, put about, backtrack, take the back track, veer round, double, wheel, countermarch, ebb, regurgitate, jib, shrink, shy, turn tail, turn round, turn upon one's heel, turn one's back upon, retrace one's steps, dance the back step, sound a retreat, beat a retreat, go home.