What does undock mean?
Undock means to separate something that has been connected or docked from its attachment. The term is especially associated with spacecraft, as when a vehicle undocks from a space station, but it can also describe removing a portable device from a charging cradle or taking a software panel away from the edge of a screen. The related noun refers to the act or event of separation: a mission delay might be described as postponing an undock. Undock is more precise than detach in technical contexts because it implies a prior connection designed to be reversed, such as a docking mechanism or an interface. Its opposite is dock. Although the word is especially common in spaceflight and computing, it can be understood literally whenever two connected things are being separated.
To detach a spacecraft, device, or interface from its connection, or to become detached.
"The capsule undocked from the spacecraft shortly before re-entry."
Usually transitive when a particular object is named, but it can also be used intransitively, especially for spacecraft.
The act or event of a spacecraft or other docked object becoming separated from its attachment.
"The scheduled undock was postponed while engineers investigated a technical problem."
The noun is relatively uncommon outside technical and spaceflight contexts.
The plural is grammatically possible but uncommon; undocking is more often used when referring to separate occurrences.
"The two undocks occurred only a few hours apart."
When two spacecraft part ways in orbit, their separation is an undock—the opposite of a docking.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does undock come from?
Undock is an English formation combining the prefix un-, meaning “reverse the action of,” with the older verb dock. Its modern uses developed alongside docking technology in aviation and spaceflight, with the sense later extending to computer interfaces and portable devices. The related forms dock, dockside, dockyard, and dockage share the same older root, although undock itself is specifically an English prefixed formation.
Related word forms
How undock is actually used
Undock is chiefly a technical verb used in spaceflight, aviation, computing, and device design. In everyday speech, it is less common than broader alternatives such as detach or disconnect.