The term 'unlucky gambler' can be summarized as a person who has lost at gambling. This person is often referred to as a 'LOSER', which is the five letter crossword solution for this term. Gambling can involve betting on games of chance, such as card games, dice games, or slot machines, and can be done in casinos, online, or even in private settings. Unfortunately, the odds are usually not in favor of the gambler, and losses are common.