dismount

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To get off or down, as from a horse.
2. v. To get out of a vehicle.
3. v. To remove from a support, setting, or mounting.
4. v. To unseat or throw off, as from a horse.
5. v. To disassemble (a mechanism, for example).
6. n. The act or manner of dismounting, especially from a horse.
7. n. Sports A move in gymnastics whereby the gymnast gets off an apparatus or completes a floor exercise, typically landing on both feet.

Century Dictionary and Cyclopedia

1. To descend from a height; come or go down.
2. To get off from a horse or other ridden animal; descend or alight, as a rider from the saddle: as, the officer ordered his troops to dismount.
3. To throw or bring down from an elevation, or from a place or post of authority.
4. To throw or bring down from a horse; unhorse: as, the soldier dismounted his adversary.
5. To remove or throw down, as cannon or other artillery from their carriages, or from a parapet or intrenchment; destroy the mountings of, so as to render useless.
6. To remove from a frame, setting, or other mounting: as, to dismount a picture or a jewel.

Wiktionary

1. n. gymnastics The part of a routine in which the gymnast detaches from an apparatus.
2. v. transitive, intransitive to get off (something)
3. v. computing, transitive to make a hard drive unavailable for use

GNU Webster's 1913

1. v. Poetic To come down; to descend.
2. v. To alight from a horse; to descend or get off, as a rider from his beast.
3. v. To throw or bring down from an elevation, place of honor and authority, or the like.
4. v. To throw or remove from a horse; to unhorse.
5. v. (Mech.) To take down, or apart, as a machine.
6. v. To throw or remove from the carriage, or from that on which a thing is mounted; to break the carriage or wheels of, and render useless; to deprive of equipments or mountings; -- said esp. of artillery.

WordNet 3.0

1. n. the act of dismounting (a horse or bike etc.)
2. v. alight from (a horse)