1
general::
1. Lacking money; also, having suffered a financial loss, as in We can't go; I'm out of pocket right now. William Congreve had it in The Old Bachelor (1693): "But egad, I'm a little out of pocket at present." [Late 1600s] 2. Referring to actual money spent, as in I had to pay the hotel bill out of pocket, but I know I'll be reimbursed. This expression sometimes occurs as a hyphenated adjective mainly in the phrase out-of-pocket expenses, as in My out-of-pocket expenses for business travel amounted to more than a thousand dollars. [Late 1800s]
American Heritage Idioms