a person who gambles for large stakes, as in a casino.
a person who spends money freely for entertainment and extravagant living.
a corporation or governmental agency that invests or spends freely or recklessly.
Origin of high roller
An Americanism dating back to 1880–85
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
slang, mainly US and Canadian a person who spends money extravagantly or gambles recklessly
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012