The word for today is…
phantasm (noun) – 1. Something apparently seen but having no physical reality; a phantom or an apparition. Also called phantasma.
2. An illusory mental image. Also called phantasma.
3. In Platonic philosophy, objective reality as perceived and distorted by the five senses.
Source : The Free Dictionary
Etymology : Phantasm is from Middle English fantasme, a borrowing from Anglo-French fantasme, which itself is a derivative of Latin and Greek words—and ultimately the Greek verb phantazein, meaning “to present to the mind.” The Greek verb took shape from phainein, meaning “to show,” and this root appears in several English words that have to do with the way things seem or appear rather than the way they really are. Phantasmagoria and diaphanous are examples. Also from this root are words such as fanciful and fantasy, in which the imagination plays an important part.