1 (count) : a set of ideas or opinions about beauty or art — usually singular
The design of the building reflects a modern/traditional/old-fashioned aesthetic.
2 a aesthetics (noncount) : the study of beauty especially in art and literature
Aesthetics is an important part of Greek philosophy.
2 b aesthetics (plural) : the artistic or beautiful qualities of something
the aesthetics of the gemstones
— aestheticism also US estheticism noun (noncount)
the aestheticism of the region