Source : Webster's Revised Unabridged Dictionary (1913)

Chirrup \Chir"rup\, v. t. [imp. & p. p. {Chirruped}; p. pr. &
   vb. n. {Chirruping}.] [See {Chirp}.]
   To quicken or animate by chirping; to cherup.

Chirrup \Chir"rup\, v. i.
   To chirp. --Tennyson.

         The criket chirrups on the hearth.       --Goldsmith.

Chirrup \Chir"rup\, n.
   The act of chirping; a chirp.

         The sparrows' chirrup on the roof.       --Tennyson.

Source : WordNet®

chirrup
     n : a series of chirps [syn: {twitter}]
     v : make high-pitched sounds; of birds [syn: {peep}, {twirp}, {cheep},
          {chirp}]