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arbiter elegantiae

American  
[ahr-bi-ter ey-le-gahn-tee-ahy, ahr-bi-ter el-uh-gan-shee-ee] / ˈɑr bɪˌtɛr ˌeɪ lɛˈgɑn tiˌaɪ, ˈɑr bɪ tər ˌɛl əˈgæn ʃiˌi /
English arbiter elegantiarum

noun

Latin.
  1. a judge of elegance or matters of taste.