harmful
/ˈhɑːmfl̩/
Proposed by a contributor, not yet supported by evidence.
Also seen as: harmfuller · harmfullest
Meaning · English
Causing or likely to cause harm or damage; injurious.
Adjective
Examples
Wear a hat to protect your skin from harmful sunlight.
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).
Common questions
What does “harmful” mean?
Causing or likely to cause harm or damage; injurious.
Is “harmful” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.