What does "deleterious" mean?

Harmful, often in a subtle or unexpected way.

What is a synonym for "deleterious"?

Common synonyms include: injurious, adverse, bad, baleful, baneful, corroding.

How do you pronounce "deleterious"?

Pronounced //ˌdɛl.ɪˈtɪə̯.ɹi.əs//.

Deleterious

/ˌdɛl.ɪˈtɪə̯.ɹi.əs/ adj

adj ·Moderate ·College level

Usage: "Deleterious" is primarily used as a adjective. Its central meaning — having lower fitness — makes it most effective in contexts where precision matters over a more general alternative.

Origin: 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.

Watch out: Writers sometimes confuse "deleterious" with "hurtful" or "injurious" — the words overlap in meaning but differ in nuance or register. Use "deleterious" when you specifically mean its core sense rather than defaulting to it as a generic substitute.

Definitions

Adjective

1
Harmful, often in a subtle or unexpected way. formal
"deleterious effects"
2
Having lower fitness.
"A deleterious mutation"

Adjective

1
harmful to living things wordnet

Synonyms

All synonyms

injurious adverse bad baleful baneful corroding

Antonyms

All antonyms

adaptive beneficent beneficial benevolent

Example

More examples

"We cannot continue to ignore the deleterious effects of these policies on our country."

Etymology

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.

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