Staringly; scrutinizingly — an onomatopoeic adverb describing staring in a rude or persistent way.
知らない人にじろじろ見られて、気まずかった。
I felt awkward being stared at by a stranger.
試験の答えをじろじろ見るのは禁止だ。
It's forbidden to stare at someone else's answers on the exam.
食事中に人の顔をじろじろ見ないでください。
Please don't stare at people's faces while they're eating.