dative singular feminine of ἀρχή
Etymology. From root *ἀρχ- (to begin, lead). The concrete sense of 'beginning' undergirds the abstract sense of 'first principle' and the social sense of 'rule' or 'authority' (that which comes first in command). Cognate with English "arch-" prefix (as in "architect," one who leads/begins the building), and Latin "arcere" (to shut in, constrain — hence 'rule').
Dictionary entry by Claude.
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