One who spends freely and extravagantly, as for luxuries or entertainment. 2. One who gambles rashly or for high stakes. 3. An organization, such as a large. This Slang page is designed to explain what the meaning of high roller is. The slang word / phrase / acronym high roller means . Online Slang Dictionary. a person who gambles or spends large sums of money Meaning, pronunciation, 'corporate jets still ferry in high rollers to the tables of Caesar's Palace'.