back

noun

1》 the rear surface of the human body from the shoulders to the hips.

    ↘the corresponding upper surface of an animal's body.

    ↘the spine.

    ↘the main structure of a ship's hull or an aircraft's fuselage.

2》 the side or part of something away from the spectator or from the direction in which it moves or faces.

    ↘the side or part of an object opposed to the one that is normally seen or used.

    ↘the part of a chair against which the sitter's back rests.

3》 a player in a team game who plays in a defensive position behind the forwards.

adverb

1》 in the opposite direction from the one that one is facing or travelling towards.

    ↘at a distance away.

    ↘(also back of) N. Amer. informal behind.

2》 so as to return to an earlier or normal position or condition.

3》 in or into the past.

4》 in return.

verb

1》 give material or moral support to.

    ↘bet money on (a person or animal) winning a race or contest.

2》 cover the back of (something) for support, protection, or decoration.

3》 (especially in popular music) provide musical accompaniment to (a singer or musician).

4》 walk or drive backwards.

    ↘(of the wind) change direction anticlockwise around the points of the compass. The opposite of veer¹.

5》 (back on/on to) (of a building or other structure) have its back facing or adjacent to.

    ↘lie behind.

adjective

1》 of or at the back.

2》 in a remote or subsidiary position.

3》 from or relating to the past: back pay.

4》 directed towards the rear or in a reversed course.

5》 Phonetics (of a sound) articulated at the back of the mouth.

Phrases

at someone's back in pursuit or support of someone.

back and forth to and fro.

back in the day in the past.

the back of beyond a very remote or inaccessible place.

back to front Brit. with the back at the front and the front at the back.

back water reverse the action of the oars to slow down or stop a boat.

behind someone's back without a person's knowledge and in an unfair way.

get (or put) someone's back up annoy or anger someone.

put one's back into approach (a task) with vigour.

turn one's back on ignore; reject.

with one's back to (or up against) the wall in a desperate situation.

Phrasal verbs

back down concede defeat.

back off draw back from action or confrontation.

back out withdraw from a commitment.

back up (of vehicles) form into a queue due to congestion.

back something up Computing make a spare copy of (data or a disk).

Derivatives

backer noun

backless adjective

backmost adjective

Origin

OE bæc, of Gmc origin.