The word "not protracted" means something that is short or brief, and its antonyms are "protracted", "extended", "lengthy", "drawn-out", "long-drawn-out", "time-consuming", "endless", "interminable", "never-ending", and "eternal". When you use antonyms for "not protracted", you can convey a sense of urgency, efficiency, and speed. For instance, instead of saying "The meeting was not protracted," you can say "The meeting was short and to the point." Similarly, instead of saying "The project did not take long," you can say "The project was completed quickly." The appropriate use of antonyms can make your writing more expressive and engaging.