Definitions of Gambling varies from each person to another. I might say that there's no wrong definition for it because it all depends on the insight of the one who engage with it. Even if someone say "Gambling is life", for some it was too shallow but for him it was very meaningful already .

Anyway, for me gambling is a serious way of entertainment but never a career. It was a poison and antidote in your life at the same time. Everything just depends on how you deal with it. So choose wisely.