adv. 25B6; adverb
William arrived promptly at 7.30 : PUNCTUALLY, on time; informal on the dot, bang on; Brit. informal spot on; N. Amer. informal on the button, on the nose.
I expect the matter to be dealt with promptly : WITHOUT DELAY, straight away, right away, at once, immediately, now, as soon as possible; QUICKLY, swiftly, rapidly, speedily, fast, expeditiously; N. Amer. momentarily; informal pronto, a.s.a.p., p.d.q. (pretty damn quick).
late, slowly.