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general::
1. Defeated; Also exhausted. For example, That horse was dead beat before the race even began, or, as Charles Dickens put it in Martin Chuzzlewit (1843): "Pull off my boots for me . . . I am quite knocked up. Dead beat." [Slang; first half of 1800s] 2. Also, deadbeat. A lazy person or loafer; also, one who does not pay debts. For example, Her housemate knew she was a deadbeat, shirking her share of the chores, or He's a deadbeat; don't count on getting that money back. [Slang; second half of 1800s]
American Heritage Idioms