The Merriam-Webster definition does not describe the purpose of gambling.
Gambling is a form of entertainment for many individuals and a form of revenue for many governments and the gaming industry.
Gambling is not meant to be a form of revenue for an individual.
It is helpful to remember that most forms of commercial entertainment (plays, concerts, dining out) have a price tag, a limited time frame, and the entertainment value is found in the activity itself.
Gambling as entertainment has no set price tag, no time frame, and the entertainment value of the activity is often dependent upon the outcome.
If you feel the need to win, order a beverage and watch the crowd. This is not the best place for you to be entertained.
If you are able to lose, decide how much you can lose and once lost, order a beverage and watch the crowd.
If you win and want to continue to enjoy the entertainment value of gambling, have a beverage and then only risk your winnings. You may win and you will lose.
Unfortunately, not everyone is capable of following these suggestions.