Lethe

UK: /ˈliːθɪ/ US: (lē′thē)

WordReference Random House Unabridged Dictionary of American English © 2026

Le•the  (lē′thē), n. 

1. Mythology [Class. Myth.] a river in Hades whose water caused forgetfulness of the past in those who drank of it.
2. (usually l.c.) forgetfulness; oblivion.

• Greek, special use of lé̄thē forgetfulness, akin to lanthánesthai to forget
• Latin

Le•the•an  (li thē′ən, lē′thē ən), Le′thied, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

Lethe / ˈliːθɪ/ noun

1. a river in Hades that caused forgetfulness in those who drank its waters
2. forgetfulness

Etymology: 16th Century: via Latin from Greek, from lēthē oblivion

Lethean / lɪˈθiːən/ adjective