Source : Webster's Revised Unabridged Dictionary (1913)

Industrious \In*dus"tri*ous\, a. [L. industrius, industriosus:
   cf. F. industrieux. See {Industry}.]
   1. Given to industry; characterized by diligence; constantly,
      regularly, or habitually occupied; busy; assiduous; not
      slothful or idle; -- commonly implying devotion to lawful
      and useful labor.

            Frugal and industrious men are commonly friendly to
            the established government.           --Sir W.
                                                  Temple.

   2. Steadily and perseveringly active in a particular pursuit
      or aim; as, he was negligent in business, but industrious
      in pleasure; an industrious mischief maker.

            Industrious to seek out the truth of all things.
                                                  --Spenser.
      -- {In*dus"tri*ous*ly}, adv. -- {In*dus"tri*ous*ness}, n.

Source : WordNet®

industriousness
     n : persevering determination to perform a task; "his diligence
         won him quick promotions"; "frugality and industry are
         still regarded as virtues" [syn: {diligence}, {industry}]