chirrup
verb
[ ˈtʃɪrəp ]
• (of a small bird) make repeated short, high-pitched sounds.
• "a bird chirruped intermittently outside"
chirrup
noun
• a short, high-pitched sound.
• "the chirrups of the crickets"
Origin:
late 16th century: alteration of chirp, by trilling the -r- .
