[ in-floo-en-zuh ]
/ ˌɪn fluˈɛn zə /


Pathology. an acute, commonly epidemic disease, occurring in several forms, caused by numerous rapidly mutating viral strains and characterized by respiratory symptoms and general prostration.Compare flu.
Veterinary Pathology. an acute, contagious disease occurring in horses and swine, characterized by fever, depression, and catarrhal inflammations of the eyes, nasal passages, and bronchi, and caused by a virus.

Nearby words

  1. influence,
  2. influence peddler,
  3. influencer,
  4. influent,
  5. influential,
  6. influenza a,
  7. influenza b,
  8. influenza c,
  9. influenza virus,
  10. influenza virus type a

Origin of influenza

1735–45; < Italian < Medieval Latin influentia influence

Related formsin·flu·en·zal, adjectivein·flu·en·za·like, adjectivepost·in·flu·en·zal, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for influenza

British Dictionary definitions for influenza


/ (ˌɪnflʊˈɛnzə) /


a highly contagious and often epidemic viral disease characterized by fever, prostration, muscular aches and pains, and inflammation of the respiratory passagesAlso called: grippe, informal flu
Derived Formsinfluenzal, adjective

Word Origin for influenza

C18: from Italian, literally: influence, hence, incursion, epidemic (first applied to influenza in 1743)

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for influenza



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 (cf. 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.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for influenza


[ ĭn′flōō-ĕnzə ]


An acute contagious viral infection, commonly occurring in epidemics or pandemics, and characterized by inflammation of the respiratory tract and by the sudden onset, fever, chills, muscular pain, headache, and severe prostration.grippe
Related formsin′flu•enzal adj.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for influenza


[ ĭn′flōō-ĕnzə ]

A highly contagious infectious disease that is caused by any of various viruses of the family Orthomyxoviridae and is characterized by fever, respiratory symptoms, fatigue, and muscle pain. It commonly occurs in epidemics, one of which killed 20 million people between 1917 and 1919.

Word History

Since ancient times, influenza has periodically swept the world. Until recently, people could not tell how this illness, which we call the flu, could spread so widely. Before people knew that organisms cause disease, they thought the stars influenced the spread of influenza. Influenza comes ultimately from the Latin word influentia, meaning “influence of the stars.” Today, however, the stars are no longer blamed for the flu. Inhaling influenza viruses causes the spread of the illness.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for influenza


[ (in-flooh-en-zuh) ]

Commonly called the flu; an acute and infectious disease of the respiratory system caused by a virus and characterized by fever, muscle pain, headache, and inflammation of the mucous membranes in the respiratory tract.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.