Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.

WORD ORIGIN

1580s, from Late Latin lethalis, alteration of Latin letalis "deadly, fatal," from letum "death," of uncertain origin. Form altered in Late Latin by association with lethe hydor "water of oblivion" in Hades in Greek mythology, from Greek lethe "forgetfulness."

MORE RELATED WORDS FOR LETHALNESS

fatality

noundeath, loss; ability to cause such
Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.