The term 'Simpson' is most commonly associated with the long-running animated television series, The Simpsons. The show follows the lives of the Simpson family, which consists of Homer, Marge, Bart, Lisa, and Maggie. The sixth letter solution for the crossword is 'Grampa, ' which is the nickname of Abraham Simpson, the patriarch of the Simpson family. He is an elderly World War II veteran who often tells stories about his past adventures.