discovered or determined by scientific observation; "variation in the ascertained flux depends on a number of factors"; "the discovered behavior norms"; "discovered differences in achievement"; "no explanation for the observed phenomena"
having once lived or existed or taken place in the real world as distinct from being legendary; "the historical Jesus"; "doubt that a historical Camelot every existed"; "actual historical events"
of or relating to the study of history; "historical scholars"; "a historical perspective"
endorsed authoritatively as having met certain requirements; "a certified public accountant"
holding appropriate documentation and officially on record as qualified to perform a specified function or practice a specified skill; "a registered pharmacist"; "a registered hospital"
having quality or payment or delivery guaranteed; "certified milk"; "certified check"; "certified mail"