Levi Strauss & Co. gave its trousers the name “jeans” after replacing the older term “waist overalls.”
The company had originally marketed its riveted trousers as waist overalls, a period expression for durable lower-body work clothing. As the garments became popular with young people, ranchers, workers, and eventually fashion consumers, the shorter word jeans became the normal public term.
Jeans is related to Genoa, the Italian port associated with the word’s history, while denim is connected with French textile terminology. These are related but different word origins, and they should not be treated as interchangeable explanations.
Levi Strauss & Co.’s terminology change took place in 1960. It marked a shift in branding and language, not the invention of the garment itself: riveted work trousers had already been sold for many decades.