A series of images, ideas, emotions, and sensations occurring involuntarily in the mind during certain stages of sleep. A daydream; a reverie. A state of abstraction; a trance. A wild fancy or hope. A condition or achievement that is longed for; an aspiration: a dream of owning their own business. One that is exceptionally gratifying, excellent, or beautiful: Our new car runs like a dream. To experience a dream in sleep: dreamed of meeting an old friend. To daydream. To have a deep aspiration: dreaming of a world at peace. To regard something as feasible or practical: I wouldn't dream of trick skiing on icy slopes. To experience a dream of while asleep: Did it storm last night, or did I dream it? To conceive of; imagine. To pass (time) idly or in reverie. dream on Informal Used in the imperative to indicate that a statement or suggestion is improbable or unrealistic. dream up To invent; concoct: dreamed up a plan to corner the market.