The Surgeon behind the Brand Name: Listerine

Joseph Lister (1827-1912) was a British surgeon (= a doctor who does operations on the body) who was the first doctor to use antiseptics (= chemicals that prevent wounds from becoming infected) during operations.
When Surgeon Joseph Lister of Glascow Royal Infirmary removed dressings from James Greenlees' compound fracture, he found the wound had healed without infection-something unheard of before. For six weeks, Lister had treated the boy's wound with carbolic acid. Now Lister had proof of success of his principle of antisepsis -which was to revolutionize methods of treatment and to open new vistas in practice of surgery, of medicine, and of environmental sanitation.
This painting by Robert A. Thom appeared in "Great Moments in Medicine" published by Parke Davis & Company, in 1966.

Listeria is the name given to any of various kinds of bacteria which cause an illness called listeriosis, a kind of food poisoning.

Listerine is a type of mouthwash (= liquid for making your mouth feel clean and smell fresh). Its original formula has notoriously strong flavour, although variations have been released that are marketed as tasting milder. The product is marketed under the slogan "Kills germs that cause bad breath".