To become completely exhausted or worn out; to be utterly tired (synonymous with 'to be worn out').
引越し作業で疲れ果てて、その夜はぐっすり眠った。
I was exhausted from the moving work and slept soundly that night.
毎日の残業で彼は心も体も疲れ果てている。
He is mentally and physically exhausted from working overtime every day.
長い山登りの後、皆が疲れ果てて座り込んだ。
After the long climb, everyone was exhausted and sat down.