1. without delay or hesitation; with no time intervening (Freq. 10) - he answered immediately - found an answer straightaway - an official accused of dishonesty should be suspended forthwith - Come here now! • Syn: immediately, instantly, straightaway, straight off, directly, now, at once, forthwith, like a shot • Derived from adjective: immediate (for: immediately) 2. at once (usually modifies an undesirable occurrence) - he promptly forgot the address • Syn: promptly