Dictionary

The rear of the body, especially the part between the neck and the end of the spine and opposite the chest and belly.

Example: Could you please scratch my back?

That which is farthest away from the front.

Example: He sat in the back of the room.

Upper part of a natural object which is considered to resemble an animal's back.

Example: The small boat raced over the backs of the waves.

A support or resource in reserve.

To go in the reverse direction.

Example: the train backed into the station;  the horse refuses to back

To support.

Example: I back you all the way;  which horse are you backing in this race?

(of the wind) To change direction contrary to the normal pattern; that is, to shift anticlockwise in the northern hemisphere, or clockwise in the southern hemisphere.

(of a square sail) To brace the yards so that the wind presses on the front of the sail, to slow the ship.

A large shallow vat; a cistern, tub, or trough, used by brewers, distillers, dyers, picklers, gluemakers, and others, for mixing or cooling wort, holding water, hot glue, etc.

A ferryboat.