In a legalistic sense, an invention can be un-invented.
The concept of invention is embodied by patent law. Patent law even defines the appropriate use of words like “patented”, “patent pending”, “invention”, and “inventor”.
For example, I created the first and original embodiment of Chromebook as a Google employee and wrote Google’s patents on Chromebook, so I’m legally the inventor of Chromebook because my name appears on all Google’s Chromebook patents. By law, no one else can claim such.
However, there are ways that a patent can be voided.
A patent can be abandoned. This happens by default if a patent isn’t defended against infringement. For example, if Samsung made their own web operating system using Google’s intellectual property, and didn’t make arrangements to license Google’s webtop patents, a court might find the patents had been abandoned. Google would no longer be able to claim any intellectual property ownership for them.
(More) Can something be un-invented?
via Answers by Jeff Nelson on Quora,