The term 'Big Pooch' can be broken down into three crossword solutions: LAB, ASTA, and ASTRO. LAB is an abbreviation for Labrador Retriever, a breed of dog that is known for its intelligence, loyalty, and friendly nature. ASTA is an abbreviation for American Staffordshire Terrier, a breed of dog that is known for its strength, courage, and tenacity. ASTRO is an abbreviation for Australian Shepherd, a breed of dog that is known for its agility, herding ability, and intelligence. Together, these three breeds make up the term 'Big Pooch, ' which is often used to refer to large, strong, and loyal dogs.