(Greek: Λήθη) is one of the five rivers of Hades. Also known as the Ameles potamos (river of unmindfulness), the Lethe flows around the cave of Hypnus and through the Underworld, where all those who drink from it experience complete forgetfulness. Lethe is also the name of the Greek spirit of forgetfulness and oblivion, with whom the river is often identified.
In Classical Greek, the word lethe literally means "oblivion", "forgetfulness", or "concealment". It is related to the Greek word for "truth", aletheia (ἀλήθεια), which through the privative alpha literally means "un-forgetfulness" or "un-concealment".