\Back"set`\, n. [Back, adv. + set.]
1. A check; a relapse; a discouragement; a setback.
2. Whatever is thrown back in its course, as water.
         Slackwater, or the backset caused by the overflow.
                                               --Harper's
                                               Mag.

\Back"set`\, v. i.
To plow again, in the fall; -- said of prairie land broken up
in the spring. [Western U.S.]