Plural of beater; devices or people that beat things, such as egg beaters, drum beaters, or those who beat carpets.
From 'beater' (one who or that which beats, from 'beat' via Old English 'beatan') plus regular English plural '-s'.
The word 'beater' is wonderfully flexible—it can mean a kitchen tool, a person, a drum stick, or a car—showing how English reuses word parts to handle new inventions without creating entirely new vocabularies.
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