Rigid Officer is a term used to describe someone who is very strict and follows rules and regulations to the letter. The term is often used to describe a military officer, but can also be used to describe someone in a position of authority in any organization. The crossword solution for this term is 'MARTINET', which is a French word meaning a strict disciplinarian. This person is known for their strict adherence to rules and regulations, and often has a reputation for being overly harsh or inflexible.