The Collaborative International Dictionary of English v.0.48:

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.
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            The pure fetters on his shins great.  --Chaucer.
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            A guinea is pure gold if it has in it no alloy. --I.
                                                  Watts.
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   2. Free from moral defilement or quilt; hence, innocent;
      guileless; chaste; -- applied to persons. "Keep thyself
      pure." --1 Tim. v. 22.
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            Now the end of the commandment is charity out of a
            pure heart, and of a good conscience. --1 Tim. i. 5.
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   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.
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            Such was the origin of a friendship as warm and pure
            as any that ancient or modern history records.
                                                  --Macaulay.
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   4. (Script.) Ritually clean; fitted for holy services.
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            Thou shalt set them in two rows, six on a row, upon
            the pure table before the Lord.       --Lev. xxiv.
                                                  6.
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   5. (Phonetics) Of a single, simple sound or tone; -- said of
      some vowels and the unaspirated consonants.
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   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.
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   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.
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The Collaborative International Dictionary of English v.0.48:

Chemistry \Chem"is*try\ (k[e^]m"[i^]s*tr[y^]; 277), n. [From
   Chemist. See Alchemy.]
   1. That branch of science which treats of the composition of
      substances, and of the changes which they undergo in
      consequence of alterations in the constitution of the
      molecules, which depend upon variations of the number,
      kind, or mode of arrangement, of the constituent atoms.
      These atoms are not assumed to be indivisible, but merely
      the finest grade of subdivision hitherto attained.
      Chemistry deals with the changes in the composition and
      constitution of molecules. See Atom, Molecule.
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   Note: Historically, chemistry is an outgrowth of alchemy (or
         alchemistry), with which it was anciently identified.
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   2. An application of chemical theory and method to the
      consideration of some particular subject; as, the
      chemistry of iron; the chemistry of indigo.
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   3. A treatise on chemistry.
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   Note: This word and its derivatives were formerly written
         with y, and sometimes with i, instead of e, in the
         first syllable, chymistry, chymist, chymical, etc., or
         chimistry, chimist, chimical, etc.; and the
         pronunciation was conformed to the orthography.
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   Inorganic chemistry, that which treats of inorganic or
      mineral substances.

   Organic chemistry, that which treats of the substances
      which form the structure of organized beings and their
      products, whether animal or vegetable; -- called also
      chemistry of the carbon compounds. There is no
      fundamental difference between organic and inorganic
      chemistry.

   Physiological chemistry, the chemistry of the organs and
      tissues of the body, and of the various physiological
      processes incident to life.

   Practical chemistry, or Applied chemistry, that which
      treats of the modes of manufacturing the products of
      chemistry that are useful in the arts, of their
      applications to economical purposes, and of the conditions
      essential to their best use.

   Pure chemistry, the consideration of the facts and theories
      of chemistry in their purely scientific relations, without
      necessary reference to their practical applications or
      mere utility.
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