Rigorous in morals or principles; uncompromising, austere.

Strict in the observance of rule, usage, etc.; formal, correct; scrupulous, particular; (occasionally) overly formal, fastidious. Also: (of a…

Extremely strict in matters of conduct or behaviour; rigorous in self-discipline and self-restraint; austere with oneself; shunning laxity or…

Puritanical; overly rigid, strict.

Undeviating in adherence to the principles or practice implied by the designation.

Of, relating to, or characteristic of a rigorist; rigoristic.