Third person singular present tense of avail; is of use or benefit to someone; helps or aids.
From Old French 'availlir' through regular verb conjugation. The third-person singular present suffix '-s' is native to Old English.
The archaic phrase 'what avails it' (what good does it do?) appears throughout Shakespeare and the King James Bible, expressing philosophical resignation—it's one of those constructions so tied to classical literature that using it now sounds instantly literary.
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