1) Ecclesiastical law expert 2) Prescript 3) Rule 4) Specialist in religious law 
• (n.) A professor of canon law; one skilled in the knowledge and practice of ecclesiastical law.
Can'on·ist noun [ Confer French canoniste .] A professor of canon law; one skilled in the knowledge and practice of ecclesiastical law. South. 
One well versed in canon or ecclesiastical law.
[adj] - pertaining to or characteristic of a body of rules and principles accepted as axiomatic 2. [n] - a specialist in canon law
adjective pertaining to or characteristic of a body of rules and principles accepted as axiomatic; e.g. `canonist communism`