someone who has no special knowledge of a subject but who expresses an opinion about it

I avoid commenting on football for fear of being called an ultracrepidarian. 我避免评论足球，因为害怕被人说成是不懂装懂。

expressing an opinion about something that you have no special knowledge of

Her ultracrepidarian husband seems to know everything about everything. 她那不懂装懂的丈夫似乎对任何事情都无所不知。