The term 'casts off' is a nautical phrase that means to leave a port or harbor. The crossword solutions for this term are 'emits, ' 'EJECTS, ' 'sheds, ' 'rids, ' 'sets sail, ' and 'JETTISONS.' 'Emits' means to send out, 'EJECTS' means to expel or throw out, 'sheds' means to get rid of, 'rids' means to free from, 'sets sail' means to begin a voyage, and 'JETTISONS' means to discard or throw overboard. All of these words can be used to describe the action of leaving a port or harbor.