plural hallucinations
: something (such as an image, a sound, or a smell) that seems real but does not really exist and that is usually caused by mental illness or the effect of a drug
He could not tell if what he was seeing was real or if it was a hallucination.
He has been having hallucinations due to the medication.
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“Hallucination.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/hallucination. Accessed 18 Jun. 2026.
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