According to Joan Coromines' Etymological Dictionary, the word flu derives from the French word grippe , which in turn derives from the Swiss-German term grüppi , which means "to bend over, curl up", or also "to shiver from cold" and "to feel ill" . In English it is called flu , short for Italian influenza , a word that was used in the 15th century to refer to the spread of a disease as the "influence" that a sick person exerted on another.
As for catarrh , the term comes from the Greek katárrhus , which means "runs (a liquid) from top to bottom", according to Coromines.
