Third person singular present tense of blatter; makes clattering or bleating noises; speaks rapidly and noisily.
From 'blatter' + '-s' (third person singular marker). Standard English verb conjugation.
The verb form 'blatters' is rarely used in writing but common in dialogue—we're more likely to write 'chattered' in formal prose but 'blatters' when mimicking crude speech.
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