Give a hoot

In the 19th century a popular expression in rural areas was “I don’t car a hooter for him,” varied with: “The money ain’t worth a hooter.” In these expressions “hooter” is thought to be a regional dialect variation of “iota,” meaning “any very small amount.” Gradually the er ending was dropped and “I don’t give a hoot,” sometimes intensified to “I don’t give a hot in hell,” became popular.