Mr. Weyerhauser is the most extensive holder and owner of unoperated pine lands in the West, or probably on the continent.
c.1600, "to be in effect," back-formation from operation, or else from Latin operatus, past participle of operari "to work, labor, toil, take pains" (in Late Latin "to have effect, be active, cause"). Surgical sense is first attested 1799. Meaning "to work machinery" is from 1864 in American English. Related: Operated; operating. Operating system in the computer sense is from 1961.
operate op·er·ate (ŏp'ə-rāt')
v. op·er·at·ed, op·er·at·ing, op·er·ates
To perform surgery.