прилагательное хитрый, коварный; действующий тайно Например: insidious disease — коварная болезнь Синоним(ы): sly, treacherous, deceitful, underhand, artful, cunning, crafty, wily
adjective Etymology: Latin insidiosus, from insidiae ambush, from insidēre to sit in, sit on, from in- + sedēre to sit — more at sit 1. a. awaiting a chance to entrap; treacherous b. harmful but enticing; seductive Example: insidious drugs 2. a. having a gradual and cumulative effect; subtle Example: the insidious pressures of modern life b. of a disease developing so gradually as to be well established before becoming apparent • insidiously adverb • insidiousness noun