Meanings
comparative more deleterious · superlative most deleterious · alternative deletorious
- formalHarmful, often in a subtle or unexpected way.
deleterious effects
4 more examples
deleterious to someone's health
Or might it suffice him, that every wholesome growth should be converted into something deleterious and malignant at his touch?
1850, Nathaniel Hawthorne, “chapter XV”, in The Scarlet LetterA trolleybus service was established by the London Passenger Transport Board between North Woolwich and Stratford on February 6, 1938, and had a deleterious effect on railway passenger traffic.
1946 May and June, J. G. Holmes, “The North Woolwich Branch”, in Railway Magazine, page 176The advent of the smartphone and its cousin the tablet was followed quickly by hand-wringing about the deleterious effects of “screen time.” But the impact of these devices has not been fully appreciated, and goes far beyond the usual concerns about curtailed attention spans.
2017 September, Jean M. Twenge, “Have Smartphones Destroyed a Generation?”, in The AtlanticSynonyms: destructive, harmful, hurtful, injurious, noxious, pernicious, harmful, damaging
Synonyms & antonyms
adjectiveHarmful, often in a subtle or unexpected way.
More synonyms by meaning
Synonym sets from Open English WordNet, CC BY 4.0.
Origin
- Ancient Greekδηλητήριος“noxious, deleterious”
- Englishdeleterious
Adapted borrowing (1640s; 1582 as deletorious) of New Latin dēlētērius, dēlētōrius + -ous, from Ancient Greek δηλητήριος (dēlētḗrios, “noxious, deleterious”), from δηλητήρ (dēlētḗr, “a destroyer”), from δηλέομαι (dēléomai, “I hurt, damage, spoil, waste”). Not related to delete or deleble. Doublet of deletery.
More words from Ancient Greek
Full word history & related roots →Translations
Bulgarian вреден
- вреден (vreden)harmful
Catalan deleteri
- deleteriharmful
Dutch schadelijk
- schadelijkharmful
Finnish haitallinen, epäsuotuisa
- haitallinenharmful
- epäsuotuisaharmful
- vahingollinenharmful
French délétère
- délétèreharmful
German schädlich, gesundheitsschädlich
- schädlichharmful
- gesundheitsschädlichharmful
Greek βλαπτικός
- βλαπτικός (vlaptikós)harmful
Italian deleterio
- deleterioharmful
Korean 해로운
- 해로운 (haeroun)harmful
Norwegian Bokmål skadelig, ødeleggende
- skadeligharmful
- ødeleggendeharmful
Polish szkodliwy
- szkodliwyharmful
Portuguese deletério
- deletérioharmful
Romanian deleter, vătămător
- deleterharmful
- vătămătorharmful
- nocivharmful
- dăunătorharmful
Russian вре́дный, вредоно́сный
- вре́дный (vrédnyj)harmful
- вредоно́сный (vredonósnyj)harmful
Scottish Gaelic sgriosail
- sgriosailharmful
Spanish deletéreo
- deletéreoharmful
Swedish menlig
- menligharmful
Turkish olumsuz, zararlı
- olumsuzharmful
- zararlıharmful
Ukrainian шкідли́вий, згу́бний
- шкідли́вий (škidlývyj)harmful
- згу́бний (zhúbnyj)harmful
Rhymes & wordplay
Rhymes with deleterious
All rhymes →Cite this entry
deleterious. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/deleterious
“deleterious.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/deleterious. Accessed November 2, 2026.
WatkinsX Dictionary, s.v. “deleterious,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/deleterious.
Source: deleterious on Wiktionary, CC BY-SA 4.0.