a (Christianity) Bound by religious rule; belonging to a monastic or religious order (often as opposed to (term|secular)). (defdate|from 14th c.)
a (geometry|of a polygon or a polyhedron) Having all sides of the same length, and all (corresponding) angles of the same size. (defdate|from 16th c.)
a Demonstrating a consistent set of rules; showing order, evenness of operation or occurrence. (defdate|from 16th c.)
a (context|now|_|rare) Well-behaved, orderly; restrained (of a lifestyle etc.). (defdate|from 16th c.)
a (grammar|of a verb, plural, etc) Following a set or common pattern; according to the normal rules of a given language. (defdate|from 17th c.)
a (context|chiefly|_|US) Having the expected characteristics or appearances; normal, ordinary, standard. (defdate|from 17th c.)
a (context|chiefly|_|military) Permanently organised; being part of a set professional body of troops. (defdate|from 17th c.)
a Having bowel movements or menstrual periods at constant intervals in the expected way. (defdate|from 18th c.)
a (analysis) (context|not comparable) (context|of a Borel measure) That every set in its domain is both outer regular and inner regular.