Katie is a diminutive of the English name Katherine, which was derived from to the Greek name Aikaterine (Αἰκατερίνη). It is associated with the Greek word katharos (καθαρός), meaning "pure". It could also have roots in the Greek word hekateros (ἑκάτερος), meaning "each of the two," or be associated with the Greek goddess Hecate, the patron of witchcraft, crossroads, and the underworld. As a stand-alone name, Katie was popular during the 1980s and 90s, although its popularity has fallen off significantly in recent years.