Read the dictionary definition of back. All definitions for this word.
1. (American football) the position of a player on a football team who is stationed behind the line of scrimmage
2. a support that you can lean against while sitting
1. the back of the dental chair was adjustable
3. the part of a garment that covers the back of your body
1. they pinned a `kick me' sign on his back
4. the protective covering on the front, back, and spine of a book
1. the book had a leather binding
5. the side that goes last or is not normally seen
1. he wrote the date on the back of the photograph
6. the posterior part of a human (or animal) body from the neck to the end of the spine
1. his back was nicely tanned
7. the series of vertebrae forming the axis of the skeleton and protecting the spinal cord
1. the fall broke his back
8. the part of something that is furthest from the normal viewer
1. he stood at the back of the stage
2. it was hidden in the rear of the store
9. (football) a person who plays in the backfield
10. strengthen by providing with a back or backing
11. establish as valid or genuine
1. Can you back up your claims?
12. shift to a counterclockwise direction
1. the wind backed
13. place a bet on
1. Which horse are you backing?
2. I'm betting on the new horse
14. travel backward
1. back into the driveway
2. The car backed up and hit the tree
15. cause to travel backward
1. back the car into the parking spot
16. support financial backing for
1. back this enterprise
17. be behind; approve of
1. He plumped for the Labor Party
2. I backed Kennedy in 1960
18. give support or one's approval to
1. I'll second that motion
2. I can't back this plan
3. endorse a new project
19. be in back of
1. My garage backs their yard
20. located at or near the back of an animal
1. back (or hind) legs
2. the hinder part of a carcass
21. related to or located at the back
1. the back yard
2. the back entrance
22. of an earlier date
1. back issues of the magazine
23. in or to or toward a past time
1. set the clocks back an hour
2. never look back
3. lovers of the past looking fondly backward
24. at or to or toward the back or rear
1. he moved back
2. tripped when he stepped backward
3. she looked rearward out the window of the car
25. in repayment or retaliation
1. we paid back everything we had borrowed
2. he hit me and I hit him back
3. I was kept in after school for talking back to the teacher
26. in or to or toward a former location
1. she went back to her parents' house
27. in or to or toward an original condition
1. he went back to sleep
28. in reply
1. he wrote back three days later