upsilon

noun

up·​si·​lon ˈüp-sə-ˌlän How to pronounce upsilon (audio) ˈyüp- How to pronounce upsilon (audio)
ˈəp-,
-lən,
 British usually  yüp-ˈsī-lən
1
: the 20th letter of the Greek alphabet see Alphabet Table
2
: 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

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

Dictionary Entries Near upsilon

Cite this Entry

“Upsilon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/upsilon. Accessed 2 Dec. 2022.

Kids Definition

upsilon

noun

up·​si·​lon ˈyüp-sə-ˌlän How to pronounce upsilon (audio) ˈəp- How to pronounce upsilon (audio)
-lən
: the 20th letter of the Greek alphabet
Υ or υ
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