Source : Webster's Revised Unabridged Dictionary (1913)

Robust \Ro*bust"\, a. [L. robustus oaken, hard, strong, fr.
   robur strength, a very hard kind of oak; cf. Skr. rabhas
   violence: cf. F. robuste.]
   1. Evincing strength; indicating vigorous health; strong;
      sinewy; muscular; vigorous; sound; as, a robust body;
      robust youth; robust health.

Source : WordNet®

robust
     adj 1: physically strong [ant: {frail}]
     2: marked by richness and fullness of flavor; "a rich ruby
        port"; "full-bodied wines"; "a robust claret"; "the robust
        flavor of fresh-brewed coffee" [syn: {full-bodied}, {rich}]
     3: strong enough to withstand intellectual challenge; "the
        experiment yielded robust results"; "a robust faith"
     4: rough and crude; "a robust tale"

Source : Free On-Line Dictionary of Computing

robust
     
        Said of a system that has demonstrated an ability to recover
        gracefully from the whole range of exceptional inputs and
        situations in a given environment.  One step below
        {bulletproof}.  Carries the additional connotation of elegance
        in addition to just careful attention to detail.  Compare
        {smart}, opposite: {brittle}.
     
        [{Jargon File}]