The superlative form of decent; of the highest degree of acceptability, reasonableness, or modesty.
The superlative form created by adding -est to the adjective decent. The word decent comes from Latin decens (fitting, suitable), so decentest means most fitting or suitable.
Regional dialects absolutely love 'decentest'—you'll hear it most in Midwestern and Northeast American English where people say 'that's the decentest thing I've heard' meaning it's totally reasonable or nice. It's actually disappearing from formal English even though it's totally grammatical!
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