If someone is on their deathbed, they are in a bed and about to die.
例句
He promised his mother on her deathbed that he would never marry.他向垂危的母親保證他絕不結婚。...after the man who murdered him nearly 40 years ago made a deathbed confession.在那個近40 年前謀殺了他的男子臨終供認了罪行之后