a hoary old joke是什么意思？

a hoary old joke

老掉牙的笑话

hoary

adj. （尤指毛发）因年老而变灰或变白的，古老的，陈旧的，灰白；

例句
...the hoary old myth that women are unpredictable.
“女人心，海底针”这种老一套的鬼话

old

adj. 老的，古老的，以前的，（用于指称被替代的东西）原来的；n. 古时；

例句
She was old enough to absent herself from the lunch table if she chose...
她长大了，可以自己做主不来吃午餐了。

joke

n. 笑话，玩笑，笑柄，笑料；vt.& vi. 开玩笑，戏弄，闹着玩，说着玩；

例句
It's bad enough to have anyone joke about such a serious matter but a member of the police force should know better.
拿这么严肃的事情开玩笑已经够糟的了，身为一名警察更不应该这样做。