Source : Webster's Revised Unabridged Dictionary (1913)

Pure \Pure\, a. [Compar. {Purer}; superl. {Purest}.] [OE. pur,
   F. pur, fr. L. purus; akin to putus pure, clear, putare to
   clean, trim, prune, set in order, settle, reckon, consider,
   think, Skr. p? to clean, and perh. E. fire. Cf. {Putative}.]
   1. Separate from all heterogeneous or extraneous matter; free
      from mixture or combination; clean; mere; simple; unmixed;
      as, pure water; pure clay; pure air; pure compassion.

            The pure fetters on his shins great.  --Chaucer.

            A guinea is pure gold if it has in it no alloy. --I.
                                                  Watts.

   2. Free from moral defilement or quilt; hence, innocent;
      guileless; chaste; -- applied to persons. ``Keep thyself
      pure.'' --1 Tim. v. 22.

            Now the end of the commandment is charity out of a
            pure heart, and of a good conscience. --1 Tim. i. 5.

   3. Free from that which harms, vitiates, weakens, or
      pollutes; genuine; real; perfect; -- applied to things and
      actions. ``Pure religion and impartial laws.'' --Tickell.
      ``The pure, fine talk of Rome.'' --Ascham.

            Such was the origin of a friendship as warm and pure
            as any that ancient or modern history records.
                                                  --Macaulay.

   4. (Script.) Ritually clean; fitted for holy services.

            Thou shalt set them in two rows, six on a row, upon
            the pure table before the Lord.       --Lev. xxiv.
                                                  6.

   5. (Phonetics) Of a single, simple sound or tone; -- said of
      some vowels and the unaspirated consonants.

   {Pure-impure}, completely or totally impure. ``The
      inhabitants were pure-impure pagans.'' --Fuller.

   {Pure blue}. (Chem.) See {Methylene blue}, under {Methylene}.
      

   {Pure chemistry}. See under {Chemistry}.

   {Pure mathematics}, that portion of mathematics which treats
      of the principles of the science, or contradistinction to
      applied mathematics, which treats of the application of
      the principles to the investigation of other branches of
      knowledge, or to the practical wants of life. See
      {Mathematics}. --Davies & Peck (Math. Dict. )

   {Pure villenage} (Feudal Law), a tenure of lands by uncertain
      services at the will of the lord. --Blackstone.

   Syn: Unmixed; clear; simple; real; true; genuine;
        unadulterated; uncorrupted; unsullied; untarnished;
        unstained; stainless; clean; fair; unspotted; spotless;
        incorrupt; chaste; unpolluted; undefiled; immaculate;
        innocent; guiltless; guileless; holy.

Source : WordNet®

pure
     adj 1: free of extraneous elements of any kind; "pure air and
            water"; "pure gold"; "pure primary colors"; "the
            violin's pure and lovely song"; "pure tones" [ant: {impure}]
     2: without qualification; used informally as (often pejorative)
        intensifiers; "an arrant fool"; "a complete coward"; "a
        consummate fool"; "a double-dyed villain"; "gross
        negligence"; "a perfect idiot"; "pure folly"; "what a
        sodding mess"; "stark staring mad"; "a thoroughgoing
        villain"; "utter nonsense" [syn: {arrant(a)}, {complete(a)},
         {consummate(a)}, {double-dyed(a)}, {everlasting(a)}, {gross(a)},
         {perfect(a)}, {pure(a)}, {sodding(a)}, {stark(a)}, {staring(a)},
         {thoroughgoing(a)}, {utter(a)}]
     3: concerned with theory and data rather than practice; opposed
        to applied; "pure science"
     4: (of color) being chromatically pure; not diluted with white
        or gray or black [syn: {saturated}] [ant: {unsaturated}]
     5: free from discordant qualities
     6: used of persons or behaviors; having no faults; sinless; "I
        felt pure and sweet as a new baby"- Sylvia Plath; "pure as
        the driven snow" [ant: {impure}]
     7: in a state of sexual virginity; "pure and vestal modesty";
        "a spinster or virgin lady"; "men have decreed that their
        women must be pure and virginal" [syn: {vestal}, {virgin},
         {virginal}, {virtuous}]
     8: not mixed; "pure oxygen" [syn: {unmixed}, {undiluted}]