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noun \ˈbak\

Simple Definition of back

  • : the rear part of the body : the part of the body that is opposite to the stomach and chest and that goes from the neck to the top of the legs

  • : the part of an animal that is like a person's back

  • : the side or surface of something that is opposite the front or face : the rear side or surface of something

Full Definition of back

  1. 1 a (1) :  the rear part of the human body especially from the neck to the end of the spine (2) :  the body considered as the wearer of clothes (3) :  capacity for labor, effort, or endurance (4) :  the back considered as the seat of one's awareness of duty or failings <get off my back> (5) :  the back considered as an area of vulnerability <the police officer's partner always watches his back> b :  the part of a lower animal (as a quadruped) corresponding to the human back c :  spinal column d :  spine 1c

  2. 2 a :  the side or surface opposite the front or face :  the rear part; also :  the farther or reverse side b :  something at or on the back for support <back of a chair> c :  a place away from the front <sat in back>

  3. 3 :  a position in some games behind the front line of players; also :  a player in this position

backed play \ˈbakt\ adjective
back·less play \ˈbak-ləs\ adjective
back of one's hand or back of the hand
  1. :  a show of contempt

back of one's mind
  1. :  the part of one's mind where thoughts and memories are stored to be drawn on

behind one's back
  1. :  without one's knowledge

in back of
  1. :  behind

Examples of back

  1. She was carrying her little daughter on her back.

  2. She has a pain in the small of her back.

  3. I slapped him on his back to congratulate him.

  4. She stabbed him in the back.

  5. He was handcuffed with his hands behind his back.

  6. a bird with a spotted back

  7. riding on the back of a horse

  8. a comfortable chair with a padded back

Origin of back

Middle English, from Old English bæc; akin to Old High German bah back, Old Norse bak

First Known Use: before 12th century




Simple Definition of back

  • : in, toward, or at the back or rear

  • : to, toward, or in the place where someone or something was previously

  • : in or into the past : backward in time

Full Definition of back

  1. 1 a :  to, toward, or at the rear b :  in or into the past :  backward in time; also :  ago c :  to or at an angle off the vertical d (1) :  under restraint (2) :  in a delayed or retarded condition

  2. 2 a :  to, toward, or in a place from which a person or thing came b :  to or toward a former state c :  in return or reply

Examples of back

  1. The soldiers moved back from the front lines.

  2. The police asked the crowd to move back from the scene of the accident.

  3. He left his friends two miles back.

  4. She turned around and looked back toward him.

  5. a chapter beginning several pages back

  6. He left his home and never went back.

  7. It's time to go back home.

  8. She took the book off the shelf and forgot to put it back.

  9. In the opening chapter the author looks back on his youth.

  10. an event back in the last century

13th Century

First Known Use of back

13th century




Simple Definition of back

  • : of or relating to the back : located at the back

  • : far from a central or main area

  • : not yet paid : owed from an earlier time

Full Definition of back

  1. 1 a :  being at or in the back <back door> b :  distant from a central or main area <back roads> c :  articulated at or toward the back of the oral passage <back vowels>

  2. 2 :  having returned or been returned

  3. 3 :  being in arrears :  overdue

  4. 4 :  moving or operating backward :  reverse

  5. 5 :  not current <back issues of a magazine>

  6. 6 :  constituting the final 9 holes of an 18-hole golf course

Examples of back

  1. He keeps his wallet in his back pocket.

  2. We came in through the back entrance.

  3. We drove on the back roads instead of the main roads.

  4. The company owes him several months in back pay.

15th Century

First Known Use of back

15th century




Simple Definition of back

  • : to give help to (someone)

  • : to bet on (someone or something)

  • : to provide evidence that supports (something)

Full Definition of back

  1. transitive verb
  2. 1 a :  to support by material or moral assistance b :  substantiate c :  to assume financial responsibility for d :  to provide musical accompaniment for —often used with up

  3. 2 a :  to cause to go back or in reverse b :  to articulate (a sound) with the tongue farther back

  4. 3 a :  to furnish with a back b :  to be at the back of

  5. intransitive verb
  6. 1 :  to move backward —often used with up

  7. 2 of the wind :  to shift counterclockwise — compare veer

  8. 3 :  to have the back in the direction of something

back·er play \ˈba-kər\ noun
back and fill
  1. 1 :  to manage the sails of a ship so as to keep it clear of obstructions as it floats down with the current of a river or channel

  2. 2 :  to take opposite positions alternately :  shilly-shally

back into
  1. :  to get into inadvertently <backed into the antiques business>

Examples of back

  1. I'm backing him for President.

  2. She backed the winner of the race and won a lot of money.

  3. She backed her argument with written evidence.

  4. She backed the singer on the guitar.

  5. She backed into a parking space.

  6. She backed out of the garage.

  7. The dog kept growling but backed off cautiously.

  8. back a skirt with stiff material


First Known Use of back


Synonym Discussion of back

support, uphold, advocate, back, champion mean to favor actively one that meets opposition. support is least explicit about the nature of the assistance given <supports waterfront development>. uphold implies extended support given to something attacked <upheld the legitimacy of the military action>. advocate stresses urging or pleading <advocated prison reform>. back suggests supporting by lending assistance to one failing or falling <refusing to back the call for sanctions>. champion suggests publicly defending one unjustly attacked or too weak to advocate his or her own cause <championed the rights of children>.

recede, retreat, retract, back mean to move backward. recede implies a gradual withdrawing from a forward or high fixed point in time or space <the flood waters gradually receded>. retreat implies withdrawal from a point or position reached <retreating soldiers>. retract implies drawing back from an extended position <a cat retracting its claws>. back is used with up, down, out, or off to refer to any retrograde motion <backed off on the throttle>.


geographical name \ˈbak\

Definition of Back

  1. river 605 miles (974 kilometers) Canada in Nunavut rising along border with Northwest Territories & flowing ENE into Arctic Ocean

Medical Dictionary


noun \ˈbak\

Medical Definition of back

  1. 1a:  the rear part of the human body especially from the neck to the end of the spineb:  the corresponding part of a lower animal (as a quadruped)c:  spinal column

  2. 2:  the part of the upper surface of the tongue behind the front and lying opposite the soft palate when the tongue is at rest

Seen and Heard

What made you want to look up back? Please tell us where you read or heard it (including the quote, if possible).


February 6, 2016

an official order, decree, or edict

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