upsilon

noun

up·si·lon ˈüp-sə-ˌlän

ˈyüp-

ˈəp-,

-lən,

British usually yüp-ˈsī-lən

: the 20th letter of the Greek alphabet see Alphabet Table

: any of a group of unstable electrically neutral elementary particles of the meson family that have a mass about 10 times that of a proton

Examples of upsilon in a Sentence

Recent Examples on the Web

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

The team is hoping to spot composite particles called upsilons, for example. —

Clara Moskowitz, Scientific American, 14 Feb. 2023

Word History

Etymology

Middle Greek y psilon, literally, simple y; from the desire to distinguish it from oi, which was pronounced the same in later Greek

First Known Use

1621, in the meaning defined at sense 1

Time Traveler

The first known use of upsilon was in 1621

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Style

“Upsilon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/upsilon. Accessed 22 Nov. 2024.

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Kids Definition

upsilon

noun

up·si·lon ˈyüp-sə-ˌlän

ˈəp-

-lən

: the 20th letter of the Greek alphabet

—Υ or υ

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upsilon

noun

Examples of upsilon in a Sentence

Word History

Dictionary Entries Near upsilon

Cite this Entry