"a seeing or hearing something which is not there," 1640s, from Latin hallucinationem (nominative hallucinatio), earlier alucinatio, noun of action from past participle stem of alucinari (see hallucinate). Related: Hallucinations.
1. Hallucination is common in patients who have suffered damage to the brain.
2. Perhaps the footprint was a hallucination.
3. High temperatures can cause hallucination.
4. There was a certain photograph about which you had a hallucination.
5. For a moment he had had an overwhelming hallucination of her presence.