Synonyms of harmful

harmful

adjective

ˈhärm-fəl 

as in detrimental

causing or capable of causing harm

DDT has been proven to be extremely harmful to the environment

Synonyms & Similar Words

• detrimental
• damaging
• dangerous
• adverse
• bad
• hazardous
• poisonous
• injurious
• deleterious
• pernicious
• evil
• hurtful
• infectious
• prejudicial
• noxious
• baneful
• mischievous
• wicked
• ill
• destructive
• nocuous
• hostile
• baleful
• unsafe
• deadly
• lethal
• infective
• risky
• venomous
• threatening
• inimical
• sinister
• unfriendly
• insidious
• ominous
• contagious
• fatal
• unhealthy
• menacing
• perilous
• unhealthful
• unwholesome
• malignant
• pestilential
• unsound
• pestiferous
• ruinous
• pestilent
• killer
• nasty
• jeopardizing
• imperiling
• parlous
• noisome

Antonyms & Near Antonyms

• harmless
• beneficial
• benign
• safe
• innocuous
• useful
• innocent
• advantageous
• inoffensive
• favorable
• good
• helpful
• healthy
• healthful
• wholesome
• propitious
• remedial
• salutary
• anodyne
• curative
• salubrious
• sound
• hurtless
• palliative
• secure
• nontoxic
• nonpoisonous
• benignant
• nondestructive
• noninfectious
• noncorrosive
• nonfatal
• nonlethal
• nonpolluting
• nonvenomous

Example Sentences

Recent Examples of harmful

Align price of alcohol with inflation Levying specific taxes on products that societies deem to be harmful, like tobacco or gambling, is an age-old concept. — Isabella Cueto, STAT, 14 July 2026

Of course, these messages may not be harmful just within online manifesting communities. — Daisy Schofield, Allure, 13 July 2026

If one copy of a gene contains a harmful mutation, for example, the second copy may still function normally, reducing the likelihood that the mutation will affect the organism. — Encyclopedia Britannica, 13 July 2026

While occasional itching is not usually harmful, persistent irritation should be taken seriously. — Sherri Gordon, Health, 13 July 2026