The superlative form of sincere; most genuine, honest, and free from deception or pretense.
From Latin 'sincerus,' possibly meaning 'clean,' 'pure,' or 'whole,' though the etymology is debated. The word entered English in the 1500s and has consistently meant genuine and honest, with 'sincerest' being its most intense form.
The phrase 'sincerest form of flattery' (imitation) is fascinating because it suggests that mimicking someone shows deeper appreciation than words—it's a way English speakers have found to use the word 'sincerest' to mean something counterintuitive!
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