I have discovered a new game. It's called Keep One / Drop One, and here is how it works. You start out with two words. For example:
Now you can choose to drop the word card and then add another word to Christmas perhaps Merry. Then you could end up with Merry Christmas,
Or you could drop Christmas, and come up with Card Game, by adding the word game to card.
You keep a word, and drop a word, and always add a new word in the process.
Now lets start the game:
The first entry is: