Spanish flu

Span·ish flu

noun \ˈspan-ish-\

Definition of SPANISH FLU

: influenza that is caused by a subtype (H1N1) of the orthomyxovirus causing influenza A and that was responsible for about 500,000 deaths in the United States in the influenza pandemic of 1918–1919—called also Spanish influenza; compare asian flu, hong kong flu