(athletics) A long-distance running race over 5000 metres.

(of a thing) Being a complete mix; containing parts of many different origins. / (informal, of a person or animal, chiefly a dog) Having ancestry of many different origins; to be of mixed race or breed.

Former designation of Nelarabine; a chemotherapy prodrug used in treatment of T-cell acute lymphoblastic leukemia.

(physics) The only stable isotope of manganese, ⁵⁵₂₅Mn, having 25 protons and 30 neutrons

(physics) A minor stable isotope of chromium, ⁵³₂₄Cr, having 24 protons and 29 neutrons; it amounts to about 9% of the element in nature

(Internet slang) Censored spelling of ass.

Alternative form of fifty-fifty

Alternative form of fifty-fifty

(physics) The naturally-occurring radioactive isotope of vanadium, ⁵⁰₂₃V, having twenty-three protons and twenty-seven neutrons; its half-life is 1.5 x 10¹⁷ years

(Canada, US, fiction) Pertaining to a fake telephone number. The local exchange and area code number 555 was reserved in North American dialing plan for fictional numbers, prior to the 21st century.