upsilon
n. உகர ஒலியுடைய கிரேக்க எழுத்து.
Up"si*lon, n. [Gr. 'y^ psilo`n bare, mere, simple y.] Defn: The 20th letter (U, u) of the Greek alphabet, a vowel having originally the sound of oo as in room, becoming before the 4th century b. c. that French u or Ger. ü. Its equivalent in English is u or y.