The Collaborative International Dictionary of English v.0.48:

Intonation \In`to*na"tion\, n. [See 1st Intonate.]
   A thundering; thunder. [Obs.] --Bailey.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Intonation \In`to*na"tion\, n. [Cf. F. intonation. See
   Intone.]
   1. (Mus.)
      (a) The act of sounding the tones of the musical scale.
      (b) Singing or playing in good tune or otherwise; as, her
          intonation was false.
      (c) Reciting in a musical prolonged tone; intonating, or
          singing of the opening phrase of a plain-chant, psalm,
          or canticle by a single voice, as of a priest. See
          Intone, v. t.
          [1913 Webster]

   2. The manner of speaking, especially the placement of
      emphasis, the cadence, and the rise and fall of the pitch
      of the voice while speaking.
      [PJC]

WordNet (r) 3.0 (2006):

intonation
    n 1: rise and fall of the voice pitch [syn: intonation,
         modulation, pitch contour]
    2: singing by a soloist of the opening piece of plainsong
    3: the act of singing in a monotonous tone [syn: intonation,
       chanting]
    4: the production of musical tones (by voice or instrument);
       especially the exactitude of the pitch relations