dock vs undock

dock is a noun but undock is not a noun.

Word	Noun	Adjective	Verb	Adverb
dock	Yes	No	Yes	No
undock	No	No	Yes	No

dock (noun)	undock (noun)
the solid bony part of the tail of an animal as distinguished from the hair
a short or shortened tail of certain animals
landing in a harbor next to a pier where ships are loaded and unloaded or repaired; may have gates to let water in or out
a platform built out from the shore into the water and supported by piles; provides access to ships and boats
an enclosure in a court of law where the defendant sits during the trial
a platform where trucks or trains can be loaded or unloaded
any of certain coarse weedy plants with long taproots, sometimes used as table greens or in folk medicine

dock (verb)	undock (verb)
maneuver into a dock	take (a ship) out of a dock
remove or shorten the tail of an animal	move out of a dock
come into dock
deduct from someone's wages
deprive someone of benefits, as a penalty