The term 'excessively proper' can be described by two crossword solutions: PRISSY (6 letters) and PRIM (4 letters). PRISSY is an adjective meaning excessively or affectedly neat, delicate, or well-behaved. It is often used to describe someone who is overly concerned with propriety or etiquette. PRIM is an adjective meaning excessively proper or precise in manner or appearance. It is often used to describe someone who is excessively formal or stiff in their behavior. Together, these two words describe someone who is excessively proper in their behavior and appearance.