We use cookies to enhance your experience on our website. By continuing to use our website, you are agreeing to our use of cookies. You can change your cookie settings at any time. Find out more

Subscriber login

Library card login

Other

Login Athens/Access Management Federation

X Close menu

Dictionary Language resources

upsilon

Pronunciation: /ʌpˈsʌɪlən, juːp-, ˈʊpsɪlɒn, ˈjuːp-/

Definition of upsilon

noun

the twentieth letter of the Greek alphabet (Υ, υ), transliterated as ‘u’ or (chiefly in English words derived through Latin) as ‘y’.
(Upsilon) [followed by Latin genitive] Astronomy the twentieth star in a constellation:Upsilon Scorpii
(also upsilon particle) Physics a meson thought to contain a b quark bound to its antiparticle, produced in particle accelerators.

Origin:

Greek, literally 'slender U', from psilos 'slender', referring to the need to distinguish upsilon from the diphthong oi: in late Greek the two had the same pronunciation