octogenarian

n person between 80 and 89 years of age 八旬老人（80至89岁之间）: She is very active for an octogenarian. 她已经是八旬老人了, 还很精神.

occurrence, ocean, ocean lane, ocean-going, oceanarium, Oceania, oceanic, oceanography, ocelot, ochre (US also ocher), Oct, oct(o)-, octagon, octagonal, octane, octane number (also `octane rating), octave, octavo, octet (also octette), October, octopus, ocular, oculist, odd, odd job man, odd jobs, odd-looking, oddball, oddity, oddly, oddment, oddness, odds, odds-on, ode, odious, odiousness, odium, odometer, odor,