Source : Webster's Revised Unabridged Dictionary (1913)

Steadfast \Stead"fast\, a. [Stead + fast, that is, fast in
   place.] [Written also stedfast.]
   1. Firmly fixed or established; fast fixed; firm. ``This
      steadfast globe of earth.'' --Spenser.

   2. Not fickle or wavering; constant; firm; resolute;
      unswerving; steady. ``Steadfast eye.'' --Shak.

            Abide steadfast unto him [thy neighbor] in the time
            of his trouble.                       --Ecclus.
                                                  xxii. 23.

            Whom resist steadfast in the faith.   --1 Pet. v. 9.

Source : WordNet®

steadfast
     adj 1: marked by firm determination or resolution; not shakable;
            "firm convictions"; "a firm mouth"; "steadfast
            resolve"; "a man of unbendable perseverence";
            "unwavering loyalty" [syn: {firm}, {steady}, {unbendable},
             {unfaltering}, {unshakable}, {unwavering}]
     2: firm and dependable especially in loyalty; "a steadfast
        ally"; "a staunch defender of free speech"; "unswerving
        devotion"; "unswerving allegiance" [syn: {staunch}, {unswerving}]