up·si·lon
noun/ʌpˈsaɪlən/, /ˈʊpsɪlɒn/
/ˈʊpsɪlɑːn/
- the 20th letter of the Greek alphabet (ϒ, υ)
希腊字母表的第 20 个字母 Word OriginGreek, literally ‘slender U’, from psilos ‘slender’, referring to the need to distinguish upsilon from the diphthong oi: in late Greek the two had the same pronunciation.