insidious

/ɪnˈsɪdi.əs/adjective

Causing damage slowly and secretly, so that it goes unnoticed at first.

Example sentences

“Rust is insidious, quietly eating away at the frame for years.”
“The disease has an insidious onset, with almost no early symptoms.”

Reserved for things that harm gradually: diseases, rumors, prejudice. Do not confuse with 'invidious', which means unfairly discriminatory.

Synonyms for insidious

stealthy
sneaky
subtle
treacherous
creeping

Often confused with insidious

insidious vs invidious

Find it in: Advanced English words.

Related words

insinuateTo suggest something unpleasant in an indirect way instead of saying it outright.insipidDull and bland; lacking flavor, character, or interest.insolentRude and disrespectful in words or behavior.instigateTo set an action or event in motion, especially by urging or encouraging others.insurmountableToo great to be overcome or dealt with.ineptLacking skill or ability; clumsy or incompetent at something.