The term OVERALL CHIEF can be solved by the crossword solution SUPREMO, which is a seven-letter word. SUPREMO is a Spanish word that means 'SUPREME' or 'highest in rank'. It is often used to refer to someone who is in charge of a large organization or enterprise, such as a CEO or president. Therefore, OVERALL CHIEF can be used to describe a person who is in charge of a company or organization and has the highest authority.