dismount

Concise Oxford English Dictionary © 2008 Oxford University Press:
dismount/dɪsˈmaʊnt/

▶verb

• 1 get off a horse, bicycle, etc.

• 2 remove (something) from its support.

• 3 Computing make (a disk or disk drive) unavailable for use.

– origin C16: from dis- + mount1, prob. on the pattern of OFr. desmonter, med. L. dismontare.