Source : Webster's Revised Unabridged Dictionary (1913)

Mortal \Mor"tal\, a. [F. mortel, L. mortalis, from mors, mortis,
   death, fr. moriri 8die; akin to E. murder. See {Murder}, and
   cf. {Filemot}, {Mere} a lake, {Mortgage}.]
   1. Subject to death; destined to die; as, man is mortal.

   2. Destructive to life; causing or occasioning death;
      terminating life; exposing to or deserving death; deadly;
      as, a mortal wound; a mortal sin.

   3. Fatally vulnerable; vital.

            Last of all, against himself he turns his sword, but
            missing the mortal place, with his poniard finishes
            the work.                             --Milton.

   4. Of or pertaining to the time of death.

            Safe in the hand of one disposing Power, Or in the
            natal or the mortal hour.             --Pope.

   5. Affecting as if with power to kill; deathly.

            The nymph grew pale, and in a mortal fright.
                                                  --Dryden.

   6. Human; belonging to man, who is mortal; as, mortal wit or
      knowledge; mortal power.

            The voice of God To mortal ear is dreadful.
                                                  --Milton.

   7. Very painful or tedious; wearisome; as, a sermon lasting
      two mortal hours. [Colloq.] --Sir W. Scott.

   {Mortal foe}, {Mortal enemy}, an inveterate, desperate, or
      implacable enemy; a foe bent on one's destruction.

Mortal \Mor"tal\, n.
   A being subject to death; a human being; man. ``Warn poor
   mortals left behind.'' --Tickell.

Sin \Sin\, n. [OE. sinne, AS. synn, syn; akin to D. zonde, OS.
   sundia, OHG. sunta, G. s["u]nde, Icel., Dan. & Sw. synd, L.
   sons, sontis, guilty, perhaps originally from the p. pr. of
   the verb signifying, to be, and meaning, the one who it is.
   Cf. {Authentic}, {Sooth}.]
   1. Transgression of the law of God; disobedience of the
      divine command; any violation of God's will, either in
      purpose or conduct; moral deficiency in the character;
      iniquity; as, sins of omission and sins of commission.

            Whosoever committeth sin is the servant of sin.
                                                  --John viii.
                                                  34.

            Sin is the transgression of the law.  --1 John iii.
                                                  4.

            I think 't no sin. To cozen him that would unjustly
            win.                                  --Shak.

            Enthralled By sin to foul, exorbitant desires.
                                                  --Milton.

   2. An offense, in general; a violation of propriety; a
      misdemeanor; as, a sin against good manners.

            I grant that poetry's a crying sin.   --Pope.

   3. A sin offering; a sacrifice for sin.

            He hath made him to be sin for us, who knew no sin.
                                                  --2 Cor. v.
                                                  21.

   4. An embodiment of sin; a very wicked person. [R.]

            Thy ambition, Thou scarlet sin, robbed this
            bewailing land Of noble Buckingham.   --Shak.

   Note: Sin is used in the formation of some compound words of
         obvious signification; as, sin-born; sin-bred,
         sin-oppressed, sin-polluted, and the like.

   {Actual sin},

   {Canonical sins},

   {Original sin},

   {Venial sin}. See under {Actual}, {Canonical}, etc.

   {Deadly}, or

   {Mortal},

   {sins} (R. C. Ch.), willful and deliberate transgressions,
      which take away divine grace; -- in distinction from
      vental sins. The seven deadly sins are pride,
      covetousness, lust, wrath, gluttony, envy, and sloth.

   {Sin eater}, a man who (according to a former practice in
      England) for a small gratuity ate a piece of bread laid on
      the chest of a dead person, whereby he was supposed to
      have taken the sins of the dead person upon himself.

   {Sin offering}, a sacrifice for sin; something offered as an
      expiation for sin.

   Syn: Iniquity; wickedness; wrong. See {Crime}.

Source : WordNet®

mortal
     adj 1: subject to death; "mortal beings" [ant: {immortal}]
     2: involving loss of divine grace or spiritual death; "the
        seven deadly sins" [syn: {deadly}, {mortal(a)}]
     3: unrelenting and deadly; "mortal enemy" [syn: {mortal(a)}]
     4: causing or capable of causing death; "a fatal accident"; "a
        deadly enemy"; "mortal combat"; "a mortal illness" [syn: {deadly},
         {deathly}]

mortal
     n : a human being; "there was too much for one person to do"
         [syn: {person}, {individual}, {someone}, {somebody}, {human},
          {soul}]