The children’s TV show “Phineas and Ferb” featured a song called “A-G-L-E-T” about — what else — the small, round, metallic or plastic tubes that cap the end of shoelaces. “Aglet” came from the French word “aiguillette,” meaning “small needle,” which makes sense, given the way they thread onto the end of a shoelace. While it seems like a modern fashion word, this term has actually been in use since the Middle Ages, likely since shoelaces were being made.