Definition
A criticism, question, remark, etc., that is expressed forcefully and causes discomfort or unease due to its intensity or because it brings up sensitive or difficult issues.
刻薄的批評（問題、評論）
She hadn't really meant to lie, but their piercing questions had forced her to.
她並不是真的想說謊，但他們尖銳的提問迫使她這麼做。
He was famous for his piercing criticism in board meetings.
他在董事會會議中以其尖銳的批評而聞名。
If you think that kind of behavior is appropriate, you need to ask yourself some piercing questions.
如果你認為那種行為是合適的，你需要問自己一些尖銳的問題。