Q:

Why haven't jurists corrected the ambiguity of 'civil law'?

Source: A Brief Introduction to Law in Canada (Mar. 2017). p. 39 Bottom. Box 2.3.

"Common Law" and "Civil Law": Alternate Meanings
As we have seen, some legal expressions have different meanings in different contexts. It addition
to referring to legal systems, the phrases "common law" and "civil law" can have other meanings, too.
  The phrase civil law is sometimes used as a synonym for private law—in other words, laws governing the relationship between persons (as opposed to public law, which deals with the legal relationship between a state and its individual members). Private and public law are generally
recognized distinctions in both common law and civil law systems (except perhaps in some so-cialist countries). Therefore, somewhat confusingly, there could be a reference to civil law (where
the context means private law) and its application in a common law jurisdiction. Adding to the
confusion is the fact that in many civil law countries, their civil codes are primarily concert*d with
private, or civil, law matters as opposed to public law ones. Criminal law and other areas of public law are frequently dealt with in other "non-code" statutes. However, the key features of civil law
systems—such as the inquisitorial approach of judges and the lack of precedent—usually apply
to these legislated areas as well.
  The phrase common law, apart from its reference to the legal system that originated in England.
can also refer to decisions by courts exercising their "common law" jurisdiction (used in contradistinction to decisions by courts exercising their "equitable" jurisdiction), and to case law generally
(used in contradistinction to legislation, or enacted laws).

This polysemy of 'civil law' (e.g. our "civil-law" tag) can be easily untangled, if 'civil law' is restricted to mean only private law OR only continental law, or if 'civil law' is abandoned and overriden with the latter two terms.
So why haven't jurists (lawyers and judges) done so?

A:

The English language does not have the equivalent of the French Academy to officially regulate questions of spelling, grammar, punctuation and word meaning. 
Jurists don't control how the language is used and for the most point don't bother to try to do so. Also, context almost always clarifies this particular ambiguity.

