Webster's Revised Unabridged Dictionary · 1913

Hallucinate

Hallucinate (hal*lū"si*nāt) , intransitive verb

[Latin hallucinatus, alucinatus, past participle of hallucinari, alucinari, to wander in mind, talk idly, dream.]

1.
To wander; to go astray; to err; to blunder; -- used of mental processes. [Rare] — Byron
2.
To perceive a non-existent object or phenomenon; to believe that one is experiencing something which in reality does not exist; to experience a hallucination{2}.

hallucinate (hal*lū"si*nāt) , transitive verb

To experience (something nonexistent) as an hallucination{2}.