1. Crazy or Insane: This is the most common meaning. It implies that someone is not thinking clearly or rationally, perhaps due to mental illness, drugs, or alcohol.
* Example: "After drinking all that wine, he was completely out of his head."
2. Unconscious or Asleep: This meaning suggests that someone is not aware of their surroundings or is in a state of deep sleep.
* Example: "He was out of his head after the surgery."
3. Forgetful or Absentminded: This meaning implies that someone is not paying attention or is having trouble remembering things.
* Example: "He was so out of his head that he forgot to pick up the kids from school."
4. Imaginary or Unrealistic: This meaning suggests that someone is thinking about things that are not real or are not possible.
* Example: "He's got his head out in the clouds, dreaming up all these impossible schemes."
To understand the specific meaning of "out of his head" in a particular sentence, you need to consider the context and the other words used around it.