What would the Double Dactyl form be without six-syllable words? Probably not nearly as funny. Long, complex, scientific words are often funny. Sinestrorotatory? Other words just feel funny in the mouth, like: widdershins, wunderkind, or didactic. Repetitive elements in words can be funny. Momentous? Nene? Mandamus? Some words are just so self-important that they are funny to see in use. So, get out in the world with your vocabulary lessons and quests, and find words that are funny, that are weird to say, and then find a way to incorporate them into your poetry.