The term 'PLAYGROUND GERM' is a reference to the game of COOTIE, which is a children's game that involves assembling a plastic bug-like creature. The six-letter solution for this term is 'COOTIE'. COOTIE is a game that has been around since the 1940s and is still popular today. It is a game that encourages creativity and problem-solving skills as players must assemble the bug-like creature using various pieces.