Deferral is the act of postponing something or putting it off until a later time. Antonyms for deferral might include advance, acceleration, promptness, immediacy, or urgency. Advance suggests moving something forward in time or bringing it closer to completion. Acceleration implies a quickening of pace or an increase in speed. Promptness suggests being on time or early. Immediacy implies an urgency or pressing need. Urgency suggests a critical situation or a need for immediate action. These antonyms highlight the opposite meanings of deferral, indicating a sense of urgency, immediacy or promptness rather than delay or postponement.