noun

• The tendency for a person to act without reference to others, particularly in matters of style, fashion or mode of thought.
• The moral stance, political philosophy, or social outlook that promotes independence and self-reliance of individual people, while opposing the interference with each person's choices by society, the state, or any other group or institution.
• (logic) The doctrine that only individual things are real.
• (philosophy) The doctrine that nothing exists but the individual self.