To regard or represent something as perfect or better than in reality. She tends to idealize her childhood, forgetting the difficult times.
To form or create an idealized version of something in one's mind. The artist idealized the landscape, removing any imperfections in his painting.
To simplify or approximate (a system, phenomenon, etc.) by assuming ideal or perfect conditions for the sake of analysis or calculation. Engineers often idealize a beam as perfectly rigid to make the calculations tractable.