illusion noun

ADJ. dangerous To believe you have nothing more to learn is a dangerous illusion. | optical, visual The road ahead looks wet, but in fact this is an optical illusion.

VERB + ILLUSION be under, entertain, have They are under no illusions about the difficulties ahead of them. | create, give (sb) The huge size of the vehicle gives the illusion of safety. | foster, maintain, preserve, sustain They are trying to maintain the illusion that the company is in good shape. | break, destroy, dispel, shatter Within the first week at university all my illusions were shattered. | shed Now is the time to shed our illusions.

PREP. ~ about/as to She had no illusions about her attractiveness to men.

PHRASES be all an illusion It turned out that their happy marriage was all an illusion.