Source : Webster's Revised Unabridged Dictionary (1913)

Sixth \Sixth\, n.
   1. The quotient of a unit divided by six; one of six equal
      parts which form a whole.

   2. The next in order after the fifth.

   3. (Mus.) The interval embracing six diatonic degrees of the
      scale.

Sixth \Sixth\, a. [From Six: cf. AS. sixta, siexta.]
   1. First after the fifth; next in order after the fifth.

   2. Constituting or being one of six equal parts into which
      anything is divided.

Source : WordNet®

sixth
     adj : coming next after the fifth and just before the seventh in
           position [syn: {6th}]

sixth
     n 1: position six in a countable series of things
     2: a sixth part [syn: {one-sixth}]
     3: the musical interval between one note and another six notes
        away from it