The Collaborative International Dictionary of English v.0.48:

Waltz \Waltz\, n. [G. walzer, from walzen to roll, revolve,
   dance, OHG. walzan to roll; akin to AS. wealtan. See
   Welter.]
   A dance performed by two persons in circular figures with a
   whirling motion; also, a piece of music composed in triple
   measure for this kind of dance.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Waltz \Waltz\, v. i. [imp. & p. p. Waltzed; p. pr. & vb. n.
   Waltzing.]
   To dance a waltz.
   [1913 Webster]

WordNet (r) 3.0 (2006):

waltz
    n 1: an assured victory (especially in an election) [syn: walk-
         in, waltz]
    2: music composed in triple time for waltzing
    3: a ballroom dance in triple time with a strong accent on the
       first beat [syn: waltz, valse]
    v 1: dance a waltz [syn: waltz, waltz around]