adjective

deleterious

del-ih-TEER-ee-uss

Deleterious (adjective) means causing harm or damage, especially gradually and to health, an environment or a system. Example: “Long hours of night work have a deleterious effect on the heart.”

adjective

Causing harm or damage, especially gradually and to health, an environment or a system.

"Long hours of night work have a deleterious effect on the heart."

"Overgrazing proved deleterious to the fragile hillside soil."

How to use deleterious

Learner’s notes

In plain EnglishBad for you, in a way that does real damage.

When to use it

Formal; most at home in scientific, medical and academic writing.

Memory tip

It takes to, not for: deleterious to health.

Trace the full origin ↓

Easily confused with

detrimental → pernicious → noxious →

Common pairings

deleterious effect deleterious impact deleterious to health deleterious consequences

Study it as flashcards or scroll it in Flow — saved to your collection.

Test yourself on “deleterious” A quick quiz — meaning, synonyms & usage →

Fill the gap

Can you complete this real example?

Long hours of night work have a _____ effect on the heart.

Etymology

From Greek dēlētērios 'noxious, destructive', from dēleisthai 'to hurt'.

Origin: Greek

Synonyms

View more →

harmful damaging injurious detrimental destructive

Antonyms

beneficial advantageous

Related words

bad wrong dangerous evil useful violent helpful productive

Rhymes for deleterious

yous nous pious joyous heinous ominous curious anxious copious tenuous tedious spurious

See all rhymes for deleterious →

Frequently asked questions

What is the difference between deleterious and detrimental?

They are close in meaning and often interchangeable. Deleterious leans towards physical or biological damage and is the commoner word in medicine and science; detrimental is more general and is used freely about careers, reputations and business.

Is deleterious too formal for everyday writing?

It is a formal word. In conversation or plain-English copy, harmful or damaging usually reads better; keep deleterious for academic, medical and legal prose.

What is the meaning of deleterious?

"deleterious" (adjective) means causing harm or damage, especially gradually and to health, an environment or a system.

What is another word for deleterious?

Other words for "deleterious" include harmful, damaging, injurious, detrimental, destructive.

People also searched

bad wrong dangerous evil useful violent helpful productive