The antonyms for the word "concretizing" would be abstracting, conceptualizing, idealizing, and generalizing. Abstracting means to extract the essential meaning or most important aspects of something. Conceptualizing is the act of forming an idea, concept, or mental representation of something. Idealizing means to represent something as perfect or ideal. Generalizing refers to making a general statement or concept about something based on limited information. All of these antonyms contrast with concretizing, which means to make something more specific or tangible. When an idea or concept is concretized, it becomes more concrete and tangible, whereas when it is abstracted, conceptualized, idealized, or generalized, it becomes more abstract and less tangible.