Source : Webster's Revised Unabridged Dictionary (1913)

Sixteenth \Six"teenth`\, a. [From {Sixteen}: cf. AS.
   sixte['o]?a.]
   1. Sixth after the tenth; next in order after the fifteenth.

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

   {Sixteenth note} (Mus.), the sixteenth part of a whole note;
      a semiquaver.

Sixteenth \Six"teenth`\, n.
   1. The quotient of a unit divided by sixteen; one of sixteen
      equal parts of one whole.

   2. The next in order after the fifteenth; the sixth after the
      tenth.

   3. (Mus.) An interval comprising two octaves and a second.
      --Moore (Encyc. of Music.)

Source : WordNet®

sixteenth
     adj : coming next after the fifteenth in position [syn: {16th}]
     n : position 16 is a countable series of things