Patent

1. adjective

   (of a bodily tube or passageway) open; affording free passage

   “patent ductus arteriosus”

2. noun

   a document granting an inventor sole rights to an invention

   Similar: patent of invention

3. adjective

   clearly revealed to the mind or the senses or judgment

   “the effects of the drought are apparent to anyone who sees the parched fields”

   Similar: apparent, evident, manifest, plain, unmistakable

4. noun

   an official document granting a right or privilege

   Similar: letters patent