Discovered, determined, or found out something as a fact through investigation or inquiry.
From Old French 'acertainer' meaning 'to make certain,' combining 'à' (to) and 'certain' (sure), literally 'to make sure' or 'to render certain.'
Ascertained is the legal and scientific word for finding truth—it implies rigorous investigation, not just guessing or assuming, which is why courts and researchers favor it over casual 'found out.'
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