noun
flu
Influenza, an infectious illness that commonly causes fever, aches, and coughing.
She stays home from work because she has the flu.
Etymology
Flu shortens influenza. The older disease name reflected a belief in an external influence causing illness; the short form keeps the established illness sense.
More examples
- A yearly flu shot helps protect against infection.
- Several students are out sick with the flu.
- He is recovering from the flu but still feels tired.
Forms
flu
Similar words
- influenza
- The full medical name for the same illness.