—v.t. 1. to alter from a settled state; cause to be no longer firmly fixed or established; render unstable; disturb: Violence unsettled the government. 2. to shake or weaken (beliefs, feelings, etc.); cause doubt or uncertainty about: doubts unsettling his religious convictions. 3. to vex or agitate the mind or emotions of; upset; discompose: The quarrel unsettled her.