intimate Having a close, personal relationship or being closely acquainted intrepid Very brave, fearless, unshakable intrinsic Belonging naturally; essential intrusive Causing disruption or annoyance through being unwelcome or uninvited. inveigh To speak or write about something with great hostility invidious likely to arouse or incur resentment or anger in others irascible Having or showing a tendency to be easily angered ironic Using words to convey a meaning that is the opposite of its literal meaning; often implies an amused or sardonic expression of some contrast in the form of satire or sarcasm irresolute showing or feeling hesitancy; uncertain jargon Special words or expressions used by a profession or group that are difficult for others to understand