Definition of omega
1
: the 24th and last letter of the Greek alphabet — see Alphabet Table
2
: the extreme or final part : end
3a
: 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
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Merriam-Webster unabridged
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Time Traveler for omega
The first known use of omega was in the 15th century
See more words from the same century