four-in-hand

n coach or carriage pulled by four horses and driven by one person 驷马车（一人驾御四匹马拉的马车）.

foul-mouthed, foul-up, foully, foulness, found, foundation, foundation course, foundation-stone, foundations, founder, founder-member, founding father, foundling, foundry, fount, fountain, fountain-head, fountain-pen, four, four-, four-letter word, four-ply, four-poster, four-square, four-wheel drive, fourfold, foursome, fourteen, fourteenth, fourth, fowl, fowl pest, fox, fox-hunting, fox-terrier, foxglove, foxhole, foxhound, foxtrot, foxy,