You can think of beater as the one tied to the action beat. Sometimes it is the thing doing the hitting: a stick on a drum, blades in an egg bowl, a flat tool on a dusty carpet, a person banging the bushes so birds fly up. And sometimes the word turns around and points at the thing that takes the hits: an old car, an old pair of shoes. So the first question is always who is beating what.
From the word’s history
Wiktionary records beater as Middle English beter, from Old English beatere (a beater; boxer, fighter; champion), that is beat + -er, and notes it is related to beetle, a type of mallet. So the oldest recorded sense is a person who hits, and the tool senses sit right beside it.
來源字典把 beater 追到中古英語 beter、古英語 bēatere（打鬥的人、拳手），也就是 beat 加 -er，並指出它和 beetle（一種木槌）有關。所以最早記到的是「動手打的人」，工具的意思就長在旁邊。
Wiktionary, English entry 'beater' (packet source_ref kaikki:3f6f69a190036ae4:514906551:39534): 'From Middle English beter, betere, bettere, from Old English bēatere... equivalent to beat + -er. Related to beetle (a type of mallet).'
登入就可以看每一支怎麼連回核心畫面。