psychol a perception that's not correct to reality, owning been altered subjectively in some way in the mind with the perceiver See also hallucination An illusion is also a thing that appears to be like or appears like something, but is either another thing or will not be there https://emiliockpuc.answerblogs.com/35997911/an-unbiased-view-of-illusion-of-kundun-mu-online