To be dilatory means to be slow or delayed in completing a task or taking an action. Antonyms of the word dilatory include prompt, punctual, quick, expeditious, and efficient. These words describe individuals or actions that prioritize completing tasks in a timely manner. Being prompt means being on time or punctual, while being quick means doing things at a fast pace. Expeditious refers to being efficient and timely in completing a task, while being efficient means achieving maximum productivity and minimum wasted effort. Therefore, using these antonyms in place of "be dilatory" shows a sense of urgency, carefulness, and efficiency in completing tasks or taking actions.