The Collaborative International Dictionary of English v.0.48:

Quickly \Quick"ly\, adv.
   Speedily; with haste or celerity; soon; without delay; quick.
   [1913 Webster]

WordNet (r) 3.0 (2006):

quickly
    adv 1: with rapid movements; "he works quickly" [syn: quickly,
           rapidly, speedily, chop-chop, apace] [ant:
           easy, slow, slowly, tardily]
    2: with little or no delay; "the rescue squad arrived promptly";
       "come here, quick!" [syn: promptly, quickly, quick]
    3: without taking pains; "he looked cursorily through the
       magazine" [syn: cursorily, quickly]

Moby Thesaurus II by Grady Ward, 1.0:

111 Moby Thesaurus words for "quickly":
   PDQ, agilely, amain, animatedly, anxiously, apace, at flank speed,
   at once, at the double, avidly, breathlessly, briefly,
   by forced marches, cursorily, decisively, directly, double-quick,
   eagerly, enthusiastically, expeditiously, fast, feverishly,
   flat-out, fleetingly, flickeringly, flittingly, for a moment,
   forthwith, furiously, hand over fist, hand over hand, hastily,
   headlong, hell for leather, hell-bent, hell-bent for election,
   helter-skelter, hotfoot, hurriedly, hurry-scurry, immediately,
   impatiently, impetuously, impulsively, in an instant,
   in double time, in double-quick time, in high, in high gear,
   in no time, in passing, in seven-league boots, instanter,
   instantly, keenly, lickety-cut, lickety-split, momentarily, nimbly,
   on the double, on the instant, on the run, on the spot, pell-mell,
   post, posthaste, precipitately, pretty damned quick, promptly,
   pronto, quick, rapidly, rashly, readily, recklessly, right away,
   right off, shortly, slapdash, smartly, snappily, speedily, spryly,
   straightaway, straightway, subito, suddenly, summarily,
   superficially, swiftly, transiently, trippingly,
   under forced draft, vivaciously, whip and spur, with a rush,
   with alacrity, with all haste, with all speed, with dispatch,
   with giant strides, with gusto, with haste, with open arms,
   with rapid strides, with relish, with speed, with zest,
   without delay, without further delay, zestfully