Tired; exhausted; feeling worn out (colloquial, originally Kansai dialect but widely used).
昨日徹夜したから今日は本当にしんどい。
I pulled an all-nighter yesterday, so I'm really exhausted today.
長時間の立ち仕事で足がしんどい。
My legs are tired from standing for so long.
今週は忙しくて精神的にもしんどいよ。
This week has been busy and mentally draining too.
Tiresome; bothersome; draining — used when something feels like a hassle or is emotionally wearing.
毎週の報告書作成が本当にしんどい。
Writing the weekly reports is really a pain.
彼の愚痴を聞くのは正直しんどいよ。
Honestly, listening to his complaints is exhausting.