Meld is a keyword action that appears in an ability on one card in a meld pair. To meld the two cards in a meld pair, put them onto the battlefield with their back faces up and combined. The resulting permanent is a single object represented by two cards. See rule 712, “Double-Faced Cards.”
July 3, 2020 · Core Set 2021
To “surveil N” means to look at the top N cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.
May 3, 2019 · War of the Spark
“Adapt N” means “If this permanent has no +1/+1 counters on it, put N +1/+1 counters on it.”
January 25, 2019 · Ravnica Allegiance
"Adapt N" means "If this permanent has no +1/+1 counters on it, put N +1/+1 counters on it."