If you save someone's bacon, you get them out of a dangerous or difficult situation. Your mother once saved my bacon, did you know that? She lent me money when I needed it. Note: One explanation for this expression is that `bacon' is related to an old word for `back', so to save your bacon meant to save your back from a beating. Another is that in the past, bacon stored during the winter had to be guarded from hungry dogs. A third explanation is that the expression was in the past thieves' slang meaning `to escape'.