Elegant, sophisticated, and showing good taste; having the qualities associated with upper-class people or high-quality things.
From 'class' (from Latin 'classis' meaning fleet or group), plus the suffix '-y.' The modern sense of 'elegant' developed in the 20th century.
It's funny how 'classy' really just means 'acting like you belong to a higher class,' which shows how language reveals that we judge people based on their perceived social rank.
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