Defeats someone or gets the better of them; to outdo or overcome someone.
From Old English 'beatan' (to beat), transformed into modern 'best' as a verb meaning to defeat. The 's' marks third person singular present tense.
The word 'best' as a verb—'to best someone'—is actually older than using 'best' as a noun for 'the best thing.' The idea was originally 'to beat,' and over time people started saying 'best' to mean the ultimate form of beating someone.
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