octagon

n (geometry 几) flat figure with eight sides and eight angles 八边形; 八角形.

occupant, occupation, occupational, occupied, occupier, occupy, occur, occur to, occurrence, ocean, ocean lane, ocean-going, oceanarium, Oceania, oceanic, oceanography, ocelot, ochre (US also ocher), Oct, oct(o)-, octagonal, octane, octane number (also `octane rating), octave, octavo, octet (also octette), October, octogenarian, octopus, ocular, oculist, odd, odd job man, odd jobs, odd-looking, oddball, oddity, oddly, oddment, oddness,