to be exhausted; to be tired out; to be worn out
長旅で疲れ切ってしまった。
I was completely worn out from the long trip.
疲れ切った顔で帰宅した父を見て、心配になった。
Seeing my father come home with a completely exhausted face made me worried.
育児と仕事で疲れ切る毎日だ。
My days are exhausting between child-rearing and work.