hallucinatory UK /həˈluː.sɪ.nə.tər.i/US /həˈluː.sɪ.nə.tɔːr.i/ adjective1 •Partaking of, or tending to produce, hallucination.hallucinatory drugThe painting had a hallucinatory quality, as if it were shifting. formsmore hallucinatory · most hallucinatory