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 particle.  Physics. any of a family of heavy, short-lived, neutral mesons that are composed of a bottom quark and its antiquark. Υ, υ

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upsilon British  

/ ˈʌpsɪˌlɒn, juːpˈsaɪlən /

noun

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

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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

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

However, if T. tau and T. upsilon are subspecies, intergrades would be expected between the ranges of the two populations and not on the northeastern and southwestern periphery of their combined ranges.

From The Amphibians and Reptiles of Michoacán, México by Duellman, William E.