Antonyms for the phrase "keeping waiting" include "immediate," "prompt," and "on-time." Other antonyms may include "timely," "expeditious," "swift," and "hasty." These words all suggest a sense of urgency or promptness, indicating the opposite of "keeping waiting." Additionally, "attention," "priority," and "consideration" are all antonyms that imply a focus on the task at hand, rather than making others wait. Ultimately, choosing antonyms for "keeping waiting" will depend on the specific context in which the phrase is being used, but using words that emphasize urgency and punctuality will generally provide a good contrast to the negative connotations of "keeping waiting.