Source : Webster's Revised Unabridged Dictionary (1913)

Ageless \Age"less\, a.
   Without old age limits of duration; as, fountains of ageless
   youth.

Source : WordNet®

ageless
     adj : continuing forever or indefinitely; "the ageless themes of
           love and revenge"; "eternal truths"; "life
           everlasting"; "hell's perpetual fires"; "the unending
           bliss of heaven" [syn: {eternal}, {everlasting}, {perpetual},
            {unending}, {unceasing}]