Definition of omega
1
: the 24th and last letter of the Greek alphabet — see Alphabet Table
2
: the extreme or final part : end
3 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
