Found to be lacking something one needs, especially money, as in Can you pay the check? I seem to be caught short. This idiom uses short in the sense of “lacking money,” a usage dating from the early 1500s.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.