adj.（尤指毛发）因年老而变灰或变白的，古老的，陈旧的，灰白
Without a word spoken, he hurried away, with his hoary head bending low.
他什么也没说, 低着白发苍苍的头, 匆匆地走了.
They discussed the hoary old problem.
他们讨论老问题.
a hoary old joke
老掉牙的笑话
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