Antonyms for the phrase "dilates upon" include "summarizes," "condenses," "abridges," "abbreviates," "shortens," "compresses," "reduces," "cuts short," "abbreviates," "precis," "synopsizes," and "succinctly speaks." It refers to the act of explaining or expanding upon a subject in great detail. Using antonyms for "dilates upon" would imply that the information is being presented in a more concise and straightforward manner. Often in conversation, people may use verbose language, and using antonyms for "dilates upon" can be an effective tool in preventing miscommunication and making for more effective communication.