An introspective person tends to look inward. They spend time with their own thoughts and feelings. They may be quiet in a group, not because they have nothing to say, but because they are busy inside. A book or a film can be introspective too — it stays close to someone's inner life instead of rushing through action. The word describes a tendency, not a one-time moment: introspection is the act; introspective is what you are like if you do that a lot. It is fairly formal, more common in writing and in talk about people or art. Though actually, introspective people are not always sad, and they are not always introverts. You can be outgoing with friends and still be introspective when you are alone. English speakers sometimes mix this word with introverted; they overlap in real life, but they do not mean the same thing.