First of all, despite sharing a word in common, the "action adventure" genre is completely different from the "adventure game" genre. I know this can be confusing, but such is the case.

Second, although I try my best, it is really hard to describe what an adventure game is to people unfamiliar with adventure games. It's like trying to describe an apple to someone who has never seen one. You can do your best... but then they say "Oh, a pear!" and you say "No, an apple is not a pear." and they say "Well, besides a few trivial differences, sure sounds like a pear to me." And they will never really know what an apple is until they come across one.

So, my suggestion is to play some adventure games. The games entered into this jam last year and the year before are adventure games, and that would be a good way to start. You can also join the Discord and ask people to suggest you some adventure games to play, and I'm sure people will have suggestions.

Zelda is definitely not an adventure game. I have played them. They are good games. They are not adventure games.

The Macventure games and Zork are certainly adventure games. Although Zork, being a text adventure, wouldn't fit into this jam.

The initial definition on Wikipedia absolutely includes the Zelda games, but they go into more detail below. Basically if it has anything more than minor action, it's not an adventure game.