An onomatopoeic word expressing irritation or annoyance; being on edge or losing patience (often used as 'iraira suru').
渋滞で２０分も動かず、いらいらしてしまった。
We were stuck in traffic for twenty minutes without moving and got irritated.
彼の遅刻が続き、チーム全体がいらいらしている。
His repeated lateness is making the whole team annoyed.
試験の結果が出るまで毎日いらいらしていた。
I was nervous and on edge every day until the exam results came out.