In a way that is genuine, real, or true to the original; not falsely or as an imitation.
From 'authentical' or 'authentic' + '-ly' (adverbial suffix). The adverbial form emerges in English by the 16th century to describe actions or states done in a genuine manner.
When someone says they're 'authentically' themselves, they're claiming an ancient philosophical ideal—but the irony is that social media makes authentic self-presentation harder, not easier, than ever before.
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