noiselessly

from WordNet (r) 3.0 (2006)

noiselessly
    adv 1: without a sound; "he stood up soundlessly and
           speechlessly and glided across the hallway and through a
           door" [syn: {noiselessly}, {soundlessly}]

from The Collaborative International Dictionary of English v.0.48

Noiseless \Noise"less\, a.
   Making, or causing, no noise or bustle; without noise;
   silent; as, the noiseless foot of time.
   [1913 Webster]

         So noiseless would I live.               --Dryden.
   [1913 Webster] -- {Noise"less*ly}, adv. -- {Noise"less*ness},
   n.
   [1913 Webster]