A misapprehension; a belief in something that is in fact not true.
Anything that seems to be something that it is not.
A magician’s trick.
The state of being deceived or misled.
Something apparently seen, heard, or sensed, but having no physical reality; an image that appears only in the mind; an illusion or delusion.
A ghost or apparition.
A placeholder for a pair of players when there are an odd number of pairs playing.
A test object. A test phantom is an object that reproduces the characteristics of human tissue.
Illusive.
Fictitious or nonexistent.