Source : Webster's Revised Unabridged Dictionary (1913)

Qualify \Qual"i*fy\, v. t. [imp. & p. p. {Qualified}; p. pr. &
   vb. n. {Qualifying}.] [F. qualifier, LL. qualificare, fr. L.
   qualis how constituted, as + -ficare (in comp.) to make. See
   {Quality}, and {-Fy}.]
   1. To make such as is required; to give added or requisite
      qualities to; to fit, as for a place, office, occupation,
      or character; to furnish with the knowledge, skill, or
      other accomplishment necessary for a purpose; to make
      capable, as of an employment or privilege; to supply with
      legal power or capacity.

            He had qualified himself for municipal office by
            taking the oaths to the sovereigns in possession.
                                                  --Macaulay.

   2. To give individual quality to; to modulate; to vary; to
      regulate.

            It hath no larynx . . . to qualify the sound. --Sir
                                                  T. Browne.

   3. To reduce from a general, undefined, or comprehensive
      form, to particular or restricted form; to modify; to
      limit; to restrict; to restrain; as, to qualify a
      statement, claim, or proposition.

   4. Hence, to soften; to abate; to diminish; to assuage; to
      reduce the strength of, as liquors.

            I do not seek to quench your love's hot fire, But
            qualify the fire's extreme rage.      --Shak.

   5. To soothe; to cure; -- said of persons. [Obs.]

            In short space he has them qualified. --Spenser.

   Syn: To fit; equip; prepare; adapt; capacitate; enable;
        modify; soften; restrict; restrain; temper.

Source : WordNet®

qualifying
     adj : referring to or qualifying another sentence element;
           "relative pronoun"; "relative clause"

qualifying
     n 1: the grammatical relation that exists when a word qualifies
          the meaning of the phrase [syn: {modification}, {limiting}]
     2: success in satisfying a test or requirement; "his future
        depended on his passing that test"; "he got a pass in
        introductory chemistry" [syn: {passing}, {pass}] [ant: {failing}]