The crossword solution for the term 'NOT A CRIMSON FAN' is ELI, which stands for ELI Whitney, an American inventor and mechanical engineer who lived in the late 18th and early 19th centuries. He is best known for inventing the cotton gin, a machine that revolutionized the production of cotton. He was not a fan of Harvard University's sports teams, the Crimson, so the answer to the crossword clue is ELI.