prior art


patent law
: knowledge that is publicly available (as from the description in an already existing patent, from publications, or from public use or sale) before the date of filing a claim for a patent for an invention
a finding by the judge that there was no advancement of design in the new invention over the prior art

Word History

First Known Use

1883, in the meaning defined above

Time Traveler
The first known use of prior art was in 1883

Dictionary Entries Near prior art

Cite this Entry

“Prior art.” Dictionary, Merriam-Webster, Accessed 1 Feb. 2023.

Legal Definition

prior art

: the processes, devices, and modes of achieving the end of an alleged invention that were known or knowable by due diligence before and at the date of the invention
also : the knowledge or description of such processes, devices, or modes
used chiefly in patent law
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