n. 25B6; noun
she's broken her back : SPINE, backbone, spinal column, vertebral column. See list at vertebra .
the back of the house : REAR, rear side, other side; Nautical stern.
the back of the queue : END, tail end, rear end, tail; N. Amer. tag end.
the back of a postcard : REVERSE, other side, underside; verso; informal flip side.
dorsal, lumbar.
front, head, face.
25B6; adverb
he pushed his chair back : BACKWARDS, behind one, to one's rear, rearwards; away, off.
a few months back : AGO, earlier, previously, before, in the past.
forward.
25B6; verb
the record companies backed the scheme with a few hundred pounds : SPONSOR, finance, put up the money for, fund, subsidize, underwrite, be a patron of, act as guarantor of; informal foot the bill for, pick up the tab for; N. Amer. informal bankroll, stake.
most people backed the idea : SUPPORT, endorse, sanction, approve of, give one's blessing to, smile on, favour, advocate, promote, uphold, champion; vote for, ally oneself with, stand behind, side with, be on the side of, defend, take up the cudgels for; second; informal throw one's weight behind.
he backed the horse at 331 : BET ON, gamble on, stake money on.
he backed away : REVERSE, draw back, step back, move backwards, back off, pull back, retreat, withdraw, give ground, backtrack, retrace one's steps.
oppose, advance.
25B6; adjective
the back seats : REAR, rearmost, hind, hindmost, hinder, posterior.
a back copy : PAST, old, previous, earlier, former, out of date.
front, future.
25A0; back down GIVE IN, concede defeat, surrender, yield, submit, climb down, concede, reconsider; backtrack, back-pedal.
25A0; back out of RENEGE ON, go back on, withdraw from, pull out of, retreat from, fail to honour, abandon, default on, repudiate, back-pedal on.
25A0; back something up SUBSTANTIATE, corroborate, confirm, support, bear out, endorse, bolster, reinforce, lend weight to.
25A0; back someone up SUPPORT, stand by, give one's support to, side with, be on someone's side, take someone's side, take someone's part; vouch for.
25A0; behind someone's back SECRETLY, without someone's knowledge, on the sly, slyly, sneakily, covertly, surreptitiously, furtively.