Source : Webster's Revised Unabridged Dictionary (1913)

Prosperous \Pros"per*ous\, a. [L. prosperus or prosper,
   originally, answering to hope; pro according to + the root of
   sperare to hope. See {Despair}.]
   1. Tending to prosperity; favoring; favorable; helpful.

            A happy passage and a prosperous wind. --Denham.

   2. Being prospered; advancing in the pursuit of anything
      desirable; making gain, or increase; thriving; successful;
      as, a prosperous voyage; a prosperous undertaking; a
      prosperous man or nation.

            By moderation either state to bear Prosperous or
            adverse.                              --Milton.

   Syn: Fortunate; successful; flourishing; thriving; favorable;
        auspicious; lucky. See {Fortunate}. --
        {Pros"per*ous*ly}, adv. -- {Pros"per*ous*ness}, n.

Source : WordNet®

prosperous
     adj 1: in fortunate circumstances financially; moderately rich;
            "they were comfortable or even wealthy by some
            standards"; "easy living"; "a prosperous family"; "his
            family is well-situated financially"; "well-to-do
            members of the community" [syn: {comfortable}, {easy},
             {well-fixed}, {well-heeled}, {well-off}, {well-situated},
             {well-to-do}]
     2: very lively and profitable; "flourishing businesses"; "a
        palmy time for stockbrokers"; "a prosperous new business";
        "doing a roaring trade"; "a thriving tourist center"; "did
        a thriving business in orchids" [syn: {booming}, {flourishing},
         {palmy}, {prospering}, {roaring}, {thriving}]
     3: marked by peace and prosperity; "a golden era"; "the halcyon
        days of the clipper trade" [syn: {golden}, {halcyon}]
     4: tending to favor or bring good luck; "miracles are
        auspicious accidents"; "encouraging omens"; "a favorable
        time to ask for a raise"; "lucky stars"; "a prosperous
        moment to make a decision" [syn: {auspicious}, {encouraging},
         {favorable}, {favourable}, {lucky}]