Dictionary.com Thesaurus.com

upsilon

American  
[yoop-suh-lon, -luhn, uhp-, yoop-sahy-luhn] / ˈyup səˌlɒn, -lən, ˈʌp-, yupˈsaɪ lən /

noun

  1. the 20th letter of the Greek alphabet (Υ, υ).

  2. the vowel sound represented by this letter.

  3. Also called upsilon particlePhysics. any of a family of heavy, short-lived, neutral mesons that are composed of a bottom quark and its antiquark. Υ, υ


upsilon British  
/ ˈʌpsɪˌlɒn, juːpˈsaɪlən /

noun

  1. the 20th letter in the Greek alphabet (Υ, υ), a vowel, transliterated as y or u

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of upsilon

First recorded in 1615–25; from Late Greek ŷ psīlón, literally, “simple u ” (to distinguish it from the digraph oi, pronounced the same in Late Greek )

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

And Last: The Empress comes down with a breakthrough case of the upsilon variant and loses her senses of taste and humor.

From Washington Post • Dec. 30, 2021

Alpha, beta, upsilon, phi / Tuition here is too damn high!

From Seattle Times • Dec. 26, 2019

Alpha, beta, upsilon, phi / Tuition here is too damn high!

From Washington Times • Dec. 26, 2019

They named the signal upsilon, after the shape of the decay-particle trajectories, which resembled the Greek letter.

From Nature • Nov. 4, 2018

Addition.—Out of the Greek i�ta, two; out of the Greek upsilon, four modifications have been evolved; viz., i and j out of ι, and u, v, w, y, out of υ. c.

From A Handbook of the English Language by Latham, R. G. (Robert Gordon)