Both Uses

elegant
in
Nature, by Emerson
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I can no longer live without elegance: but a countryman shall be my master of revels.†
*
That they have some high-fenced grove, which they call a park; that they live in larger and better-garnished saloons than he has visited, and go in coaches, keeping only the society of the elegant, to watering-places, and to distant cities, are the groundwork from which he has delineated estates of romance, compared with which their actual possessions are shanties and paddocks.†

Definitions:

(1) (elegant as in: an elegant gown)
refined and tasteful in appearance, behavior or style
(2) (elegant as in: as elegant equation)
a solution that is simpler (and often more comprehensive) than most would anticipate
(3) (meaning too rare to warrant focus)