plural omegas
1
: the 24th and last letter of the Greek alphabet see Alphabet Table
2
: the extreme or final part : end compare alpha see also alpha and omega
3
: something or someone designated with the name omega or the Greek letter ω especially denoting the last in position, order, or class
"Omega-3" refers to the position of the final double bond in the chemical structure, which is three carbon atoms from the "omega," or tail end of the molecular chain.Ruairi Robertson
4
a
: a negatively charged elementary particle that has a mass 3270 times the mass of an electron

called also omega minus

b
: a very short-lived unstable meson with mass 1532 times the mass of an electron

called also omega meson

Word History

Etymology

Middle English, from Greek ō mega, literally, large o

First Known Use

15th century, in the meaning defined at sense 1

Time Traveler
The first known use of omega was in the 15th century

Dictionary Entries Near omega

Cite this Entry

“Omega.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/omega. Accessed 22 Jul. 2024.

Kids Definition

omega

noun
: the 24th and last letter of the Greek alphabet
Ω or ω
Etymology

from Greek ō mega, literally, "big o"

Medical Definition

omega

adjective
ome·​ga
variants or ω-
ō-ˈmeg-ə, -ˈmā-gə, especially British ˈō-meg-ə
: of, relating to, or being a chemical group or position at the end of a molecular chain
omega oxidation of fatty acids

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