deleterious
del-uh-TEER-ee-uhs/ˌdɛ.ləˈtɪɹ.i.əs/UKdel-i-TEER-ee-uhs/ˌdɛl.ɪˈtɪə̯.ɹi.əs/
- 1Harmful, often in a slow or hidden way.
Too much sun can have deleterious effects on your skin.
The new rule was deleterious to small shops in town.
UsageSay a deleterious effect on or deleterious to; harmful means the same.
Similarharmful, damaging, detrimental, injurious, adverse
Oppositebeneficial, harmless, salutary, benign
Use it in a sentence
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Origin
From a Greek word meaning "harmful", from a word for "destroyer". It is not related to delete.
Checked 30 Oct 2026 · 3 facts
- Deleterious derives ultimately from Ancient Greek dēlētḗrios, meaning harmful. en.wiktionary.org
- The Greek adjective derives from a word meaning destroyer. en.wiktionary.org
- Deleterious is not etymologically related to delete. en.wiktionary.org