Not principal.

Of a person or a person's character, speech, actions, etc.: simple, rustic; lacking sophistication or refinement; (hence) ignorant, uneducated. Obs…

Of persons, their qualities, etc.: Having imperfections or failings; apt to do wrong or come short of duty.

Of a person or group of people: subordinate, inferior (to another); of a lower rank. Now chiefly in critical and cultural theory, esp. post-colonial…

Auxiliary, subordinate. Obsolete. rare.

Having faults of character, faulty.

Inferior, subordinate.