It's been spelled Taekwondo, Taekwon-Do, Tae Kwon Do, and TaeKwon Do, but, essentially, the word for the martial art boils down to three parts in the original Korean: tae, meaning "to kick" or otherwise cause damage with your foot, gwon, meaning "to punch", and do, meaning "the way". Together, this is interpreted as meaning "the way of kicking and punching". Asian etymologies are really hard for me to do, because they combine parts of characters and can't really be traced the way English ones can, so I won't comment further on something I don't know much about. However, let's talk about form. Of all the capitalizations and spellings since the word's introduction in the 1960s, the different capitalizations of taekwondo and Taekwondo are about tied for usages, in both literature and Google searches. The other terms exist but are less frequent.
Hello! I'm Adam Aleksic. This year, I graduated from Harvard University with a degree in Government and Linguistics. There, I co-founded the Harvard Undergraduate Linguistics Society and wrote a thesis on Serbo-Croatian language policy, magna cum laude. In addition to etymology, I also really enjoy philosophy, trivia, vexillology, geography, board games, conlanging, art history, and law.