UPSILON

upsilon

(noun) the 20th letter of the Greek alphabet

Source: WordNet® 3.1

Etymology

Noun

upsilon (plural upsilons or upsila)

The twentieth letter of Classical and Modern Greek; the twenty-second letter of Old and Ancient Greek.

(particle physics) An upsilon meson, or bottomonium.

Synonyms

• (uncommon) ypsilon

Anagrams

• Poulins, pulsion, unspoil

Source: Wiktionary

Up"si*lon, n. [Gr. 'y^ psilo`n bare, mere, simple y.]

Definition: 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.

Source: Webster’s Unabridged Dictionary 1913 Edition