The superlative form of 'choosy,' meaning the most picky or particular.
From the adjective 'choosy' plus the superlative suffix '-est,' used to indicate the highest degree of the quality.
Superlatives like 'choosiest' were once formed with 'most' for all adjectives, but English speakers shortened common ones into '-est' forms, which is why we say 'biggest' but 'most helpful'—a split that still confuses learners!
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