a.

1. 頑皮的，淘氣的；撒野的
   You ought to be stricter with him. He's very naughty.

   你該對他更嚴格一些。他很調皮。

2. 【婉】猥褻的，淫亂的
   Nice boys do not use naughty words.

   好孩子不說下流話。

adj.

1. (especially of a child) disobedient; badly behaved.
2. informal mildly rude or indecent.
3. archaic wicked.