noun
honest person; conscientious person
Describes a person who is scrupulously honest, dutiful, and reliable, often to a degree that can be seen as overly rigid or inflexible.
彼は律儀者だから、約束は必ず守る。
He is a conscientious person, so he always keeps his promises.
あの律儀者が遅刻するなんて、何かあったに違いない。
For that honest person to be late, something must have happened.
Compound of 律儀 (honesty, conscientiousness) and 者 (person). The base word 律儀 originally referred to adherence to Buddhist precepts or rules, later broadening to general honesty and dutifulness.