[ del-i-teer-ee-uhs ]
/ ˌdɛl ɪˈtɪər i əs /


injurious to health: deleterious gases.
harmful; injurious: deleterious influences.

Origin of deleterious

1635–45; < Greek dēlētḗrios destructive, adj. derivative of dēlētḗr destroyer, equivalent to dēlē- variant stem of dēleîsthai to hurt, injure + -tēr agent suffix + -ios adj. suffix; see -ious

OTHER WORDS FROM deleterious Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for deleterious

British Dictionary definitions for deleterious

/ (ˌdɛlɪˈtɪərɪəs) /


harmful; injurious; hurtful

Derived forms of deleterious

deleteriously, adverbdeleteriousness, noun

Word Origin for deleterious

C17: from New Latin dēlētērius, from Greek dēlētērios injurious, destructive, from dēleisthai to hurt
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for deleterious

[ dĕl′ĭ-tîrē-əs ]


Having a harmful effect; injurious.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.