dismount

Etymology

dis- + mount, probably a calque of Old French desmonter.

verb

1. (transitive, intransitive) To (cause to) get off (something).
   She carefully dismounted from the horse.
   She carefully dismounted the horse.
   Cadel Evans was the first to suffer, quickly dismounting and waiting to take a bike from one of his BMC Racing team-mates, only to discover that the first of them had also punctured. July 15 2012, Richard Williams, Tour de France 2012: Carpet tacks cannot force Bradley Wiggins off track, Guardian Unlimited
2. (computing, transitive, intransitive) To make (a mounted drive) unavailable for use.
   The VMS operator tried to dismount the Unix hard drive with the DISMOUNT DISK$NFSMOUNT command, instead of umount /mnt/nfshome.
   PROBLEM: A volume periodically dismounts. There are two drives with one volume on each. From time to time, the second volume dismounts and the drive shuts down. 1995, Rick Sant'Angelo, NetWare unleashed, page 1130
3. (intransitive) To come down; to descend.
4. (military, transitive) To throw (cannon) off their carriages.

noun

1. (gymnastics) The part of a routine in which the gymnast detaches from an apparatus.
   It was a stylish routine, let down by a sloppy dismount.