old boy

n.老同学；(招呼用)老朋友，老弟，老兄

oil-fired, oil-painting, oil-palm, oil-tanker, oilcake, oilcan, oilcloth, oiled, oilfield, oiliness, oilskin, oily, ointment, okapi, okay, okay (also OK), okey, okra, old, old age, old boy (fem 阴性作 `old girl), Old English, old fogey (US old fogy), old folk, old folks' home, old girl, Old Glory, Old Harry (also Old Nick, Old Scratch), old lady, old lag, old maid, old man, old man's beard, old master, old school, old stager, old sweat, old woman, old-fashioned, old-maidish,