Superlative form of curious; the most curious, inquisitive, or unusual.
From curious + -est (superlative suffix). English forms superlatives with -est for one or two syllable adjectives; curiosest represents an older or more emphatic form compared to modern 'most curious.'
Using 'curiousest' instead of 'most curious' sounds Shakespearean and old-fashioned, which is exactly why it feels more dramatic—the extra effort of saying it makes it feel more intense, like you're really committed to how curious something is.
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