insidious

views updated Jun 27 2018

in·sid·i·ous / inˈsidēəs/ • adj. proceeding in a gradual, subtle way, but with harmful effects: sexually transmitted diseases can be insidious and sometimes without symptoms. ∎  treacherous; crafty: tangible proof of an insidious alliance.DERIVATIVES: in·sid·i·ous·ly adv.in·sid·i·ous·ness n.

insidious

views updated Jun 11 2018

insidious XVI. — L. insidiōsus, f. insidiæ ambush, trick, rel. to insidēre sit in or upon, be settled, f. IN-1 + sedēre SIT; see -IOUS.

insidious

views updated May 29 2018

insidious (in-sid-iŭs) adj. describing a disease that develops gradually and imperceptibly.