fool about/around
1．spend time idly or aimlessly；waste time虚度光阴；无所事事
He spends so much time fooling around that he never accomplishes anything．他虚度光阴大多，所以一事无成。
They fooled around too much with minor details．他们在次要的细节上浪费了太多的时间。
The teacher told the students not to fool about， but to get down to work．老师嘱咐学生们不要虚度光阴，要认真学习。
2．play and joke ；spend time foolishly with little result； trifle干蠢事；胡闹；鬼混；玩弄
He is capable， but he fools around too much．他很能干，但是他蠢事干得太多。
The monitor told his classmates not to fool about in the classroom while they should be reviewing their lessons．班长叫同学们在应当复习功课的时候不要在教室里胡闹。
Everyone knows he's been fooling around with some girl at the office．人人都知道他一直在办公室与某个姑娘鬼混。
Don't fool around with the knife，you may cut yourself．不要玩弄刀，会划破皮的。