1743, borrowed during an outbreak of the disease in Europe, from Italian influenza "influenza, epidemic," originally "visitation, influence (of the stars)," from Medieval Latin influentia (see influence). Used in Italian for diseases since at least 1504 (as in influenza di febbre scarlattina "scarlet fever") on notion of astral or occult influence. The 1743 outbreak began in Italy. Often applied since mid-19c. to severe colds.