1 upsilon | Definition of upsilon
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upsilon

noun
up·​si·​lon | \ ˈüp-sÉ™-ËŒlän How to pronounce upsilon (audio) , ˈyüp-, ˈəp-, -lÉ™n, British usually yüp-ˈsÄ«-lÉ™n How to pronounce upsilon (audio) \

Definition of upsilon

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

First Known Use of upsilon

1621, in the meaning defined at sense 1

History and Etymology for upsilon

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

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Rhyming Dictionary: Words that rhyme with upsilon

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