Source : Webster's Revised Unabridged Dictionary (1913)

Endless \End"less\, a. [AS. endele['a]s. See {End}.]
   1. Without end; having no end or conclusion; perpetual;
      interminable; -- applied to length, and to duration; as,
      an endless line; endless time; endless bliss; endless
      praise; endless clamor.

   2. Infinite; excessive; unlimited. --Shak.

   3. Without profitable end; fruitless; unsatisfying. [R.]
      ``All loves are endless.'' --Beau. & Fl.

   4. Void of design; objectless; as, an endless pursuit.

   {Endless chain}, a chain which is made continuous by uniting
      its two ends.

   {Endless screw}. (Mech.) See under {Screw}.

   Syn: Eternal; everlasting; interminable; infinite; unlimited;
        incessant; perpetual; uninterrupted; continual;
        unceasing; unending; boundless; undying; imperishable.

Source : WordNet®

endless
     adj 1: tiresomely long; seemingly without end; "endless debates";
            "an endless conversation"; "the wait seemed eternal";
            "eternal quarreling"; "an interminable sermon" [syn: {eternal},
             {interminable}]
     2: infinitely great in number; "endless waves"
     3: having no known beginning and presumably no end; "the
        dateless rise and fall of the tides"; "time is endless";
        "sempiternal truth" [syn: {dateless}, {sempiternal}]
     4: having the ends united so as to form a continuous whole; "an
        endless chain"
     5: occurring so frequently as to seem ceaseless or
        uninterrupted; "a child's incessant questions"; "your
        perpetual (or continual) complaints" [syn: {incessant}, {perpetual}]