noun
right of prior use; prior use rights
Legal term in patent law: the right of a party that was already using an invention before another party filed a patent application to continue using it.
特許法では、先使用権が認められる場合がある。
Under patent law, a right of prior use may be recognized in some cases.
Compound of 先 (prior), 使用 (use), and 権 (right). The term is a direct translation of the legal concept 'right of prior use'.