Chapter Bachelor's button to Backlog of B by Webster's Dictionary (1913 Edition)

6. The part of a cutting tool on the opposite side from its edge; as, the back of a knife, or of a saw.

7. A support or resource in reserve.

This project
Should have a back or second, that might hold,
If this should blast in proof.
Shak.

8. (Naut.) The keel and keelson of a ship.

9. (Mining) The upper part of a lode, or the roof of a horizontal underground passage.

10. A garment for the back; hence, clothing. [Obs.]

A bak to walken inne by daylight.
Chaucer.

Behind one's back, when one is absent; without one's knowledge; as, to ridicule a person behind his back. — Full back, Half back, Quarter back (Football), players stationed behind those in the front line. — To be or lie on one's back, to be helpless. — To put, or get, one's back up, to assume an attitude of obstinate resistance (from the action of a cat when attacked). [Colloq.] — To see the back of, to get rid of. — To turn the back, to go away; to flee. — To turn the back on one, to forsake or neglect him.

Back
(Back), a.

1. Being at the back or in the rear; distant; remote; as, the back door; back settlements.

2. Being in arrear; overdue; as, back rent.

3. Moving or operating backward; as, back action.

Back charges, charges brought forward after an account has been made up. — Back filling (Arch.), the mass of materials used in filling up the space between two walls, or between the inner and outer faces of a wall, or upon the haunches of an arch or vault. — Back pressure. (Steam Engine) See under Pressure. — Back rest, a guide attached to the slide rest of a lathe, and placed in contact with the work, to steady it in turning. — Back slang, a kind of slang in which every word is written or pronounced backwards; as, nam for man. — Back stairs, stairs in the back part of a house; private stairs. Also used adjectively. See Back stairs, Backstairs, and Backstair, in the Vocabulary. — Back step (Mil.), the retrograde movement of a man or body of men, without changing front. — Back stream, a current running against the main current of a stream; an eddy. — To take the back track, to retrace one's steps; to retreat. [Colloq.]

Back
(Back) v. t. [imp. & p. p. Backed ; p. pr. & vb. n. Backing.]

1. To get upon the back of; to mount.

I will back him [a horse] straight.
Shak.

2. To place or seat upon the back. [R.]

Great Jupiter, upon his eagle backed,
Appeared to me.
Shak.

3. To drive or force backward; to cause to retreat or recede; as, to back oxen.

4. To make a back for; to furnish with a back; as, to back books.