insidious
/ɪnˈsɪdɪəs
/adjective
Proceeding in a gradual, subtle way, but with very harmful effects: sexual harassment is a serious and insidious problem...
- Nuclear disc lesions are of gradual or insidious onset, the history may be on and off back pain for weeks and back pain getting worse.
- The obstruction and harassment is subtle but insidious and seriously affects the ability of the aid agencies to do their job.
- It need by no means be obvious: it can be insidious and subtle.
Synonyms
stealthy, subtle, surreptitious, sneaking, cunning, crafty, Machiavellian, artful, guileful, sly, wily, tricky, slick, deceitful, deceptive, dishonest, underhand, backhanded, indirect
informal sneaky
Derivatives
insidiousness
/ noun ...- But for five Irish teenagers, the magnifying glass doesn't reveal the insidiousness of California - it only inflates its lure and significance.
- Slowly, with an insidiousness no one recognized, those businesses began to disappear until now many of the buildings sit empty and abandoned.
- Asthma has become a common ailment in modern society, as the deteriorating environment and stress work their insidiousness against the human body.
Origin
Mid 16th century: from Latin insidiosus 'cunning', from insidiae 'an ambush or trick', from insidere 'lie in wait for', from in- 'on' + sedere 'sit'.