The term SUB STANDARD can be broken down into two crossword solutions: SONAR (5 letters) and PEPPERONI (9 letters). Sonar is a technology used to detect objects underwater by emitting sound waves and measuring the time it takes for them to bounce back. Pepperoni is a type of Italian-American cured meat made from pork and beef, usually served as a topping on pizzas. Both terms are used to describe something that is not up to the expected quality or level.