The term 'come aboard' can be broken down into four crossword solutions: JOIN (4 letters), AFFILIATE (9 letters), ASEA (4 letters), and HOPON (5 letters). To JOIN is to become part of a group or organization, while to AFFILIATE is to become associated with a larger organization. ASEA is an acronym for the Association of Southeast Asian Nations, which is a regional intergovernmental organization made up of 10 countries in Southeast Asia. Finally, hopon is a slang term meaning to JOIN or become part of something. All of these words can be used to describe the phrase 'come aboard, ' which generally means to JOIN or become part of a group or organization.