The term 'highly successful' can be described by the crossword solutions SOCKO, BIG, and BOFFO. SOCKO is an informal term used to describe something that is very successful or impressive. BIG is an acronym for 'Business Impact Group', which is a group of people who are highly successful in their respective fields. BOFFO is an acronym for 'Box Office Financial Film Organization', which is an organization that tracks the success of films at the box office. All three terms indicate that something is highly successful.