The crossword solution for the term 'ONES LEFT BEHIND' is TIPS. This is an acronym for 'To Insure Prompt Service, ' which is a phrase used in the hospitality industry to refer to the practice of leaving a gratuity for service personnel such as waiters, bartenders, and housekeepers. It is customary to leave a tip to show appreciation for good service, and it is often seen as a way of compensating service personnel for their hard work.