back

n., adv., v., & adj.
—n.
1 a the rear surface of the human body from the shoulders to the hips. b the corresponding upper surface of an animal's body. c the spine (fell and broke his back). d the keel of a ship.
2 a any surface regarded as corresponding to the human back, e.g. of the head or hand, or of a chair. b the part of a garment that covers the back.
3 a the less active or visible or important part of something functional, e.g. of a knife or a piece of paper (write it on the back). b the side or part normally away from the spectator or the direction of motion or attention, e.g. of a car, house, or room (stood at the back).
4 a a defensive player in field games. b this position.
5 (the Backs) the grounds of Cambridge colleges which back on to the River Cam.
—adv.
1 to the rear; away from what is considered to be the front (go back a bit; ran off without looking back).
2 a in or into an earlier or normal position or condition (came back late; went back home; ran back to the car; put it back on the shelf). b in return (pay back).
3 in or into the past (back in June; three years back).
4 at a distance (stand back from the road).
5 in check (hold him back).
6 (foll. by of) US behind (was back of the house).
—v.
1 tr. a help with moral or financial support. b bet on the success of (a horse etc.).
2 tr. & intr. move, or cause (a vehicle etc.) to move, backwards.
3 tr. a put or serve as a back, background, or support to. b Mus. accompany.
4 tr. lie at the back of (a beach backed by steep cliffs).
5 intr. (of the wind) move round in an anticlockwise direction.
—adj.
1 situated behind, esp. as remote or subsidiary (backstreet; back teeth).
2 of or relating to the past; not current (back pay; back issue).
3 reversed (back flow).
Phrases and idioms:
at a person's back in pursuit or support. at the back of one's mind remembered but not consciously thought of. back and forth to and fro. back bench a back-bencher's seat in the House of Commons. back-bencher a member of Parliament not holding a senior office. back-boiler Brit. a boiler behind and integral with a domestic fire. back-breaking (esp. of manual work) extremely hard. back country esp. Austral. & NZ an area away from settled districts. back-crawl = BACKSTROKE. back-cross Biol.
1 cross a hybrid with one of its parents.
2 an instance or the product of this. back door a secret or ingenious means of gaining an objective. back-door adj. (of an activity) clandestine, underhand (back-door deal). back down withdraw one's claim or point of view etc.; concede defeat in an argument etc. back-down n. an instance of backing down. back-fill refill an excavated hole with the material dug out of it.
back-formation
1 the formation of a word from its seeming derivative (e.g. laze from lazy).
2 a word formed in this way.
back number
1 an issue of a periodical earlier than the current one.
2 sl. an out-of-date person or thing. the back of beyond a very remote or inaccessible place.
back off
1 draw back, retreat.
2 abandon one's intention, stand, etc. back on to have its back adjacent to (the house backs on to a field). back out (often foll. by of) withdraw from a commitment. back passage colloq. the rectum.
back-pedal (-pedalled, -pedalling; US -pedaled, -pedaling)
1 pedal backwards on a bicycle etc.
2 reverse one's previous action or opinion. back-projection the projection of a picture from behind a translucent screen for viewing or filming. back room (often (with hyphen) attrib.) a place where secret work is done. back-scattering the scattering of radiation in a reverse direction. back seat an inferior position or status. back-seat driver a person who is eager to advise without responsibility (orig. of a passenger in a car etc.). back slang slang using words spelt backwards (e.g. yob). back-stop = LONGSTOP. back talk US = BACKCHAT. back to back with backs adjacent and opposite each other (we stood back to back). back-to-back adj. esp. Brit. (of houses) with a party wall at the rear.
back to front
1 with the back at the front and the front at the back.
2 in disorder. back-to-nature (usu. attrib.) applied to a movement or enthusiast for the reversion to a simpler way of life.
back up
1 give (esp. moral) support to.
2 Computing make a spare copy of (data, a disk, etc.).
3 (of running water) accumulate behind an obstruction.
4 reverse (a vehicle) into a desired position.
5 US form a queue of vehicles etc., esp. in congested traffic. back water reverse a boat's forward motion using oars. get (or put) a person's back up annoy or anger a person. get off a person's back stop troubling a person. go back on fail to honour (a promise or commitment). know like the back of one's hand be entirely familiar with. on one's back injured or ill in bed. on the back burner see BURNER. put one's back into approach (a task etc.) with vigour. see the back of see SEE(1).
turn one's back on
1 abandon.
2 ignore. with one's back to (or up against) the wall in a desperate situation; hard-pressed.
Derivatives:
backer n. (in sense 1 of v.). backless adj.
Etymology: OE baeligc f. Gmc