itself

/ɪtˈsɛlf/
pronoun
  1. Used to refer to a thing or animal that has already been mentioned, when that thing or animal does something to or for itself.
    • The door locked itself when we left.
    • The cat cleaned itself after eating.
    • The computer turns itself off after an hour.
  2. Used to emphasize a particular thing or animal.
    • The movie itself was good, even though the ending was confusing.
    • The house itself is beautiful, but the garden needs work.
    • The idea itself is simple, but it took a long time to develop.
  3. Used in phrases like 'by itself' meaning alone or without help, or 'in itself' meaning considering only that thing.
    • The machine can run by itself once you press start.
    • The plant grew by itself without any fertilizer.
    • The problem in itself is not difficult, but the time limit makes it hard.