Making quick, sharp, clicking sounds in quick succession; also means to move with such sounds, or to make someone nervous.
From Middle English ratelen, possibly imitative of the sound itself. The word likely developed from onomatopoeia, mimicking the actual sound of rapid clicking.
Onomatopoeia like 'rattle' are words that sound like what they describe—and linguists think these imitative words are among the very oldest human words because our ancestors just copied the sounds they heard in nature to name things.
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