Kiss Goodbye is a phrase that is used to express a fond farewell. It is often used when saying goodbye to someone who is leaving for a long period of time or when saying goodbye to someone who has passed away. The crossword solutions for the term Kiss Goodbye are LOSE (4 letters) and MISSING (7 letters). LOSE is an action verb that means to be deprived of something or to fail to keep or retain something. MISSING is an adjective that describes something that cannot be found or is absent.