"Definition" is a commercial version of the traditional family game of "Dictionary". Here, the players start with their rockets in Earth and have to reach Mars by earning votes for their definitions of weird words and points for guessing what the true definition of those words is. In each turn a referee player, who changes after the end of the turn, draws a card in which different eccentric words are specified. The rest of the players write down a definition for the word secretly on a piece of paper. Then, the referee reads aloud all definitions and players have to vote which one they think is true (they cannot vote their own definition). According to the number of votes received for their definition or if they where able to find the true definition, the players can move their rockets towards Mars. Also, the dice can determine if the players ought to write a funnier definition instead of trying to find the true one, or if instead of a word it's a famous star that they have to define, or if the definition is given to them instead of the word and they have to find this last one. The first player in Mars wins the game.