略語大辞典 [Med] 9 FUO fever of unknown origin 原因不明熱. fever of unknown origin; or fever of undetermined origin; or fever of obscure origin; or pyrexia of unknown origin; or unexplained fever; or obscure fever; or idiopathic fever; defined as an illness characterized by a temperature greater than 1 丸善「略語大辞典」JLogosID : 11875480