kastige
Kastige is a term sometimes used in German-speaking regions, particularly in Austria, to describe a somewhat old-fashioned, perhaps slightly stuffy or conservative manner of behaving or speaking. It can imply a sense of being overly proper, rigid, or even a bit prudish. The word doesn't typically carry a strong negative connotation, but rather suggests a certain adherence to traditional social norms and expectations, sometimes to the point of appearing out of touch with contemporary trends.
A person described as kastige might be perceived as being very particular about rules, etiquette, and appearances.