Doth is an old English word that means “does.” You'll find it in plays by Shakespeare and in the King James Bible, written over 400 years ago. When Shakespeare's character Hamlet says “The lady doth protest too much,” he means “The lady protests too much.” When someone in an old story says “He doth work hard,” they mean “He does work hard.”

English speakers stopped using doth in everyday conversation centuries ago, but you'll still encounter it when reading classic literature or hearing quotations from historical texts. The word was part of a whole system of old verb forms that included thou (you), hath (has), and dost (do).

Sometimes people use doth today as a joke or to sound fancy and old-fashioned, like saying “Methinks it doth rain outside!” instead of “I think it's raining!” But in Shakespeare's time, doth was just the normal way people talked.