The Collaborative International Dictionary of English v.0.48:

Aside \A*side"\, adv. [Pref. a- + side.]
   1. On, or to, one side; out of a straight line, course, or
      direction; at a little distance from the rest; out of the
      way; apart.
      [1913 Webster]

            Thou shalt set aside that which is full. --2 Kings
                                                  iv. 4.
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            But soft! but soft! aside: here comes the king.
                                                  --Shak.
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            The flames were blown aside.          --Dryden.
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   2. Out of one's thoughts; off; away; as, to put aside gloomy
      thoughts. "Lay aside every weight." --Heb. xii. 1.
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   3. So as to be heard by others; privately.
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            Then lords and ladies spake aside.    --Sir W.
                                                  Scott.
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   To set aside (Law), to annul or defeat the effect or
      operation of, by a subsequent decision of the same or of a
      superior tribunal; to declare of no authority; as, to set
      aside a verdict or a judgment.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Aside \A*side"\, n.
   Something spoken aside; as, a remark made by a stageplayer
   which the other players are not supposed to hear.
   [1913 Webster]

WordNet (r) 3.0 (2006):

aside
    adv 1: on or to one side; "step aside"; "stood aside to let him
           pass"; "threw the book aside"; "put her sewing aside when
           he entered"
    2: out of the way (especially away from one's thoughts); "brush
       the objections aside"; "pushed all doubts away" [syn:
       aside, away]
    3: not taken into account or excluded from consideration; "these
       problems apart, the country is doing well"; "all joking
       aside, I think you're crazy" [syn: apart, aside]
    4: in a different direction; "turn aside"; "turn away one's
       face"; "glanced away" [syn: away, aside]
    5: placed or kept separate and distinct as for a purpose; "had a
       feeling of being set apart"; "quality sets it apart"; "a day
       set aside for relaxing" [syn: aside, apart]
    6: in reserve; not for immediate use; "started setting aside
       money to buy a car"; "put something by for her old age"; "has
       a nest egg tucked away for a rainy day" [syn: aside, by,
       away]
    n 1: a line spoken by an actor to the audience but not intended
         for others on the stage
    2: a message that departs from the main subject [syn:
       digression, aside, excursus, divagation,
       parenthesis]

Moby Thesaurus II by Grady Ward, 1.0:

100 Moby Thesaurus words for "aside":
   a huis clos, all, apart, askance, askant, askew, aslant, aslope,
   asquint, away, awry, back, behind closed doors, beside,
   between the teeth, broadside, broadside on, by, crabwise,
   discursion, divagation, downgrade, downhill, each, edgeway,
   edgeways, edgewise, episode, excursion, excursus, glancingly,
   in a whisper, in an aside, in camera, in chambers,
   in executive session, in juxtaposition, in privacy, in private,
   in private conference, in privy, in reserve, infix, injection,
   insert, insertion, insinuation, intercalation, interjection,
   interlineation, interlocution, interpolation, introduction,
   januis clausis, laterad, laterally, monodrama, monologue, monology,
   nearby, nigh, obiter dictum, obliquely, on its side, on one side,
   on the beam, on the side, out of earshot, parenthesis, per,
   per capita, privately, privily, remark, right and left, round,
   side remark, sideling, sidelong, sideward, sidewards, sideway,
   sideways, sidewise, sidling, slant, slantingly, slantways,
   slantwise, slaunchways, slopeways, soliloquy, solo, sotto voce,
   to one side, to the side, tossing-in, wide apart, wide away,
   with bated breath