Evey first-year law student is confused by the use of the phrase "civil law" to mean two completely different things. There's civil law as opposed to common law, and then there is civil law as opposed to criminal law. I wonder: How did it happen that the same phrase came to be used to mean two different things?

  I understand that the use of "civil law" as opposed to common law comes from the Romans. The Roman empire set forth its law in compliations collectively handed down as the Corpus Juris Civilis, which I gather translates to something like "the body of law of the citizens," and so legal systems based on Roman law are "civil law" systems. Or so a little googling tells me. But how did we start to use "civil" to mean "non-criminal"? If there are any legal historians out there, latin geeks, or anyone else who might know the answer, please fill us in.