error,fallacy,hallucination,illusion,phantasm.

A delusion is a mistaken conviction, an illusion a mistaken perception or inference. An illusion may be wholly of the senses; a delusion always involves some mental error. In an optical illusion the observer sees either what does not exist, or what exists otherwise than as he sees it, as when in a mirage distant springs and trees appear close at hand. We speak of the illusions of fancy or of hope, but of the delusions of the insane. A hallucination is a false image or belief which has nothing, outside of the disordered mind, to suggest it; as, the hallucinations of delirium tremens. Compare [DECEPTION]; [INSANITY].

Antonyms:

actuality,certainty,fact,reality,truth,verity.

DEMOLISH.

Synonyms:

destroy,overthrow,overturn,raze,ruin.

A building, monument, or other structure is demolished when reduced to a shapeless mass; it is razed when leveled with the ground; it is destroyed when its structural unity is gone, whether or not its component parts remain. An edifice is destroyed by fire or earthquake; it is demolished by bombardment; it is ruined when, by violence or neglect, it has become unfit for human habitation. Compare [ABOLISH]; [BREAK].

Antonyms: