HideawayHideaway is a triggered ability. “Hideaway N” means “When this permanent enters, look at the top N cards of your library. Exile one of them face down and put the rest on the bottom of your library in a random order. The exiled card gains ‘The player who controls the permanent that exiled this card may look at this card in the exile zone.’”
Previously, the rules for the hideaway ability caused the permanent to enter the battlefield tapped, and the number of cards the player looked at was fixed at four. Cards printed before this rules change had the printed text “Hideaway” with no numeral after the word. Those older cards have received errata in the Oracle card reference to have “Hideaway 4” and the additional ability “[This permanent] enters tapped.” (CR 702.75) 4 (When this artifact enters, look at the top four cards of your library,
exileTo exile an object, move it to the exile zone from wherever it is. See rule 406, “Exile.” (CR 701.13) one face down, then put the rest on the bottom in a random order.)
Whenever this Vehicle deals combat damage to a player, you may
castTo cast a spell is to take it from the zone it’s in (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. A player may cast a spell if they have priority. See rule 601, “Casting Spells.”
To cast a card is to cast it as a spell. (CR 701.5) the exiled card without paying its mana cost. If you do, return this Vehicle to its owner's hand.
CrewCrew is an activated ability of Vehicle cards. “Crew N” means “Tap any number of other untapped creatures you control with total power N or greater: This permanent becomes an artifact creature until end of turn.”
A creature “crews a Vehicle” when it’s tapped to pay the cost to activate a Vehicle’s crew ability.
A Vehicle is “crewed by” a creature if that creature was tapped to pay the cost to activate that Vehicle’s crew ability.
If an effect states that a creature “can’t crew Vehicles,” that creature can’t be tapped to pay the crew cost of a Vehicle.
Some Vehicles have abilities that trigger when they become crewed. “Whenever [this Vehicle] becomes crewed” means “Whenever a crew ability of [this Vehicle] resolves.” If that ability has an intervening “if” clause that refers to information about the creatures that crewed it, it means only creatures that were tapped to pay the cost of the crew ability that caused it to trigger. (CR 702.122) 2