english
1
general::
1. Be tired out, exhausted, as in I can't walk another step; I'm all in. [Slang; second half of 1800s] 2. In card games, especially poker, be out of money, as in I'm finished for the night; I'm all in. It refers to having put all of one's money in the pot. In his historical dictionary of slang, J.E. Lighter suggests that the gambling usage, first recorded in 1907, may be the source of the first sense.
American Heritage Idioms
2
general::
Phrase(s): all in completely tired. • I’m all in. I need some rest. • After their 10-mile hike the campers were all in and very hungry.
McGrawhill's American Idioms And Phrasal Verbs