To stare at someone/something fixedly and often rudely; to scrutinize or look someone up and down.
知らない人にじろじろ見られて気分が悪かった。
I felt uncomfortable because a stranger stared at me.
店員が客の服装をじろじろ見るのは失礼だ。
It's rude for a shop assistant to stare critically at a customer's clothes.
彼は新入社員をじろじろ見て、何か欠点を探しているようだった。
He stared at the new employee as if looking for faults.