Gesundheit (German pronunciation (help·info)) (IPA pronunciation: [ɡəˈzʊntˈhaıt]) is the German word for health. When a person sneezes, Germans typically say Gesundheit! to wish them good health. This expression has found its way into the English language via Ashkenazi Jews (gezundheit) who were immigrating in large masses to the United States during the early twentieth century. It is sometimes used instead of the more common "bless you".
Often the word, when used in an English context, is mispronounced as [ɡəˈzʊnˈtaıd], and misspelled as "gazoontite".
Gesundheit is also used in Australia. It was imported to South Australia through the Evangelical Lutheran refugees who fled the established Lutheran church in the east of Germany. These Silesian immigrants spoke their own language until the two World Wars caused a dramatic decline in the use of German in Australia. Gesundheit was used until recent times by the majority English speaking population. Its usage seems now to have declined.
There are different theories regarding the origin of this phrase. One idea is that the expression stems from the Middle Ages when the Bubonic Plague was threatening European health. In this case the person saying gesundheit was actually wishing good health upon themselves, since they may have been infected by the one who sneezed. During this time it was also commonly believed that sneezing made one's body vulnerable to evil spirits. Thus another plausible explanation is that gesundheit was a blessing to ward off demons while the sneezer's body was defenseless.
Superstitions date back as early as Ancient Greece (ref. Herodotus, History 440 BC). The soul was thought to leave the body through the nose upon death, so a powerful sneeze was thus considered an ominous event.
The following is a Jewish perspective on the custom: Although not technically part of Jewish Law (Halacha), the custom of saying gezuntheit, tzu gezunt, labreeyut, or God bless you is considered a mannerly custom. It is written in the Talmud that the patriarch Jacob was the first person to become ill before passing on. Before that, people would sneeze and die. When God infused the soul into Man, He "blew it" into Adam's nostrils. Thus, when it came time for the soul to be returned to its Maker, it would leave through the same portal it arrived.