What is the meaning of Phantom?

A ghost or apparition.

Something apparently seen, heard, or sensed, but having no physical reality; an image that appears only in the mind; an illusion or delusion.

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.

Source: wiktionary.org