Meaning & use
deleterious
Last updated
UK/ˌdeləˈtɪəriəs/
US/ˌdeləˈtɪriəs/
Meaning
adjectivebefore a noun
Causing harm or damage, often gradually or in ways that are not immediately obvious.
Grammar: Most common in deleterious effect/impact on; predicative use is possible but stiff: The effect was deleterious.
Patterns
- deleterious effect on
- deleterious impact on
- deleterious to something
The report described the deleterious effect of noise on sleep.
Cheap repairs can be deleterious to old buildings.
Common combinations
- deleterious effect on
- Lack of shade has a deleterious effect on garden soil.
- deleterious impact on
- The policy had a deleterious impact on small firms.
- deleterious to health
- Prolonged stress is deleterious to health.
Synonyms and how they differ
- harmful
- Harmful is the everyday general word; deleterious is more formal and often gradual.
- damaging
- Damaging can be sudden and visible, while deleterious often suggests hidden or long-term harm.
- detrimental
- Detrimental is very close in register and also pairs with to or effect on.
Opposites
Commonly confused: deleterious or delirious?
deleterious vs delirious
Delirious means confused or wildly excited; deleterious means harmful.
Practice
The study measured the ___ effects of chronic sleep loss on memory.
Choose one answer.
The formal collocation is deleterious effects on. Delirious is a near-spelling distractor but means confused or wildly excited.
Make it your own
Write a sentence using “deleterious”, then check it and compare it with the examples above.
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