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English definition of “keystone”

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keystone

noun [C] uk   /ˈkiː.stəʊn/ us    /-stoʊn/

keystone noun [C] (STONE)

specialized architecture the middle stone in the top of an arch that has a special shape and holds all the other stones in position

keystone noun [C] (IMPORTANT PART)

the most important part of a plan, idea, etc. on which everything else depends
Translations of “keystone”
in Chinese (Traditional) 石, 拱頂石, 塞縫石…
in Chinese (Simplified) 石, 拱顶石, 塞缝石…
(Definition of keystone from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
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