Sideboard
noun
(furniture) A piece of dining room furniture having drawers and shelves for linen and tableware; originally for serving food.
A board or similar barrier that forms part of the side of something.
(collectible card games) A set of cards that are separate from a player's primary deck, used to customize a match strategy against an opponent by enabling a player to change the composition of the playing deck.
verb
(collectible card games) To include (a card) in one's sideboard.
To add sideboards to.