A trick is a set of 4 cards, one from each player. Also known as "book".

Trump
A card suit that wins a trick when another suit has been led. In Spades, ♠ always wins and can only be beaten by higher ♠.

Dump
A card (usually high in rank) which is played in a way to avoid taking a trick. In Spades, only ♣️, ♦️, and ♥️ can be dumped. Also known as "slough" or "sluff".

Bid
The number of tricks the players on a team are contracted to take. Each player makes a separate bid and the combined bid is the goal.

Nil
A bid of zero tricks after you have seen your cards. This is a somewhat risky play with a big reward when it is done successfully.

Points
A unit of counting in the scoring of a game. Points scored are computed by comparing a team's combined bids against their tricks taken.

Round
A round starts with dealing 13 cards to each player. A round concludes after all 13 cards are played by each player. Also known as "deal" or "hand".

Game
A game is all of the rounds put together and ends when you reach the predetermined score (250, 500 points).

Team
A team is a pair of partner players who compete against another team. A team's bids and tricks are combined for scoring. Also known as "partnership".