I never heard that the Adventure term came from Colossal Cave Adventure, really ? It's true that it is/was the other term commonly used for this kind of games, anyhow.
Myst was better categorized as a puzzle game, you wouldn't recommend it to someone looking for games similar to Monkey Island
It's a well established term, and puzzle games like Myst are generally considered a subgrenre: https://en.wikipedia.org/wiki/Adventure_game