the.com/deadbeat

means A person who fails to pay debts or meet basic obligations (especially financial or familial ones) while carrying on as if nothing's owed.

from Born in 19th-century American slang, originally meaning someone 'beaten' or worn down to worthlessness — a loafer or sponger with nothing left to give. By the late 1800s it had narrowed onto the specific sin of not paying what you owe, and 'deadbeat dad' later sharpened it further into a term for a parent who skips out on child support. The 'dead' here means utterly, completely — same intensifying sense as 'dead tired' — not a corpse, just a beat so thorough there's nothing left to collect.