The term 'BIG PITCH' can be broken down into two words, 'BIG' and 'PITCH'. The first word, 'BIG', is defined as having a great size or importance. The second word, 'PITCH', is defined as an attempt to persuade someone to do or buy something. When combined, the term 'BIG PITCH' can be interpreted as an important attempt to persuade someone to do or buy something. In the context of the crossword, the answer to the clue 'BILLBOARD' is a 9 letter word, which is 'BIG PITCH'. This term is often used in the advertising industry to refer to a large-scale marketing campaign that is designed to attract attention and persuade people to purchase a product or service.