1. to perceive something (such as a sight, sound, or smell) that is not actually present; to experience a hallucination
Usage: transitive or intransitive; often used in medical or psychological contexts
2. to have false or distorted perceptions due to illness, drugs, or extreme stress
Usage: medical/clinical usage

Examples

• After the high fever, the patient began to hallucinate and see strange shapes on the walls.
• The drug can cause users to hallucinate vivid colors and sounds.
• Sleep deprivation may cause a person to hallucinate.
• He hallucinates conversations with people who are not in the room.
• The doctor asked if the patient hallucinates or hears voices.
• Without water in the desert, travelers sometimes hallucinate mirages.
• She hallucinates due to her medical condition and takes medication to manage it.