Source : Webster's Revised Unabridged Dictionary (1913)

Intone \In*tone"\, v. t. [imp. & p. p. {Intoned}; p. pr. & vb.
   n. {Intoning}.] [LL. intonare, intonatum; pref. in- in + L.
   tonus tone. See {Tone} and cf. {Entune}, {Intonate}.]
   To utter with a musical or prolonged note or tone; to chant;
   as, to intone the church service.

Intone \In*tone"\, v. i.
   To utter a prolonged tone or a deep, protracted sound; to
   speak or recite in a measured, sonorous manner; to intonate.
   --Pope.

Source : WordNet®

intone
     v 1: utter monotonously and repetitively and rhythmically; "The
          students chanted the same slogan over and over again"
          [syn: {tone}, {chant}]
     2: recite with musical intonation; recite as a chant or a
        psalm; "The rabbi chanted a prayer" [syn: {chant}, {intonate},
         {cantillate}]
     3: speak carefully, as with rising and falling pitch or in a
        particular tone; "please intonate with sadness" [syn: {intonate}]