The Collaborative International Dictionary of English v.0.48:

Handily \Hand"i*ly\ (-[i^]*l[y^]), adv. [See Handy.]
   In a handy manner; skillfully; conveniently.
   [1913 Webster]

WordNet (r) 3.0 (2006):

handily
    adv 1: in a convenient manner; "the switch was conveniently
           located" [syn: handily, conveniently] [ant:
           inconveniently]
    2: with no difficulty; "she beat him handily" [syn: handily,
       hands down]

Moby Thesaurus II by Grady Ward, 1.0:

50 Moby Thesaurus words for "handily":
   ably, adeptly, adroitly, advantageously, agilely, aptly, artfully,
   artistically, brilliantly, capably, cleverly, comfortably,
   competently, conveniently, cunningly, deftly, dexterously,
   dextrously, easily, effectively, effectually, efficiently,
   effortlessly, excellently, expertly, featly, functionally,
   ingeniously, masterfully, neatly, nimbly, practically,
   proficiently, profitably, readily, resourcefully, serviceably,
   skillfully, spryly, superbly, to advantage, to good effect,
   to good use, to profit, usefully, well, with consummate skill,
   with finesse, with genius, with skill