Originally Posted by ypsieast

Gambling: To bet on an uncertain outcome, as of a contest

Yes, by definition, poker is gambling. Money is bet on uncertain outcomes. This is a fact and the nature of the game.

What differenciates poker from other forms of gambling is that the level of uncertainty of outcomes is changing. Not only that, but it changes by a wide margin from one situation to the next. Furthermore, poker allows the participants great control over their finacial exposure to different situations, based on their analysis of the outcome's (un)certainty. i.e. the difference of financial exposure between folding pf and pushing all in is huge and is at the discretion of the player.
A roulette wheel or slot machine offers no variance on the uncertainty of outcomes. Its always the same.
Blackjack offers little control of financial exposure. BJ players put their money in before they get any cards. There is just a very small ability to increase finacial exposure upon realizing a more certain (less uncertain) outcome (doubling down etc..).

For Poker, it is this highly scalable ability to increase fiancial exposure to more certain outcomes (what we call EV+ play) that makes it a game of skill.