on your last legs
US /ɑn yʊər læst lɛɡz/
UK /ɑn yʊər læst lɛɡz/

1.
快不行了, 精疲力尽
about to fail, collapse, or die; in a very weak or poor condition
:
•
My old car is really on its last legs; I need to get a new one soon.
我的旧车真的快不行了;我很快就需要买一辆新车。
•
After working for 12 hours, I was completely on my last legs.
工作了12小时后,我完全精疲力尽了。