{ ||Or"ga*non (?), ||Or"ga*num (?), } n. [NL. organon, L. organum. See Organ.] An organ or instrument; hence, a method by which philosophical or scientific investigation may be conducted; -- a term adopted from the Aristotelian writers by Lord Bacon, as the title ("Novum Organon") of part of his treatise on philosophical method. Sir. W. Hamilton.