It’s easily to do a little research and see that many think the word “guitar” probably comes from the ancient Greek word κιθάρα or kithara. Mythology attributes Hermes with creating the first kithara from a tortoise shell. So much for my tree question.
Some other words and terms that are related to guitar are gittern, the vihuela, the four-course Renaissance guitar, and the five-course baroque guitar. These all have distinctive personalities. They come in different sizes but look at least like they are related to the modern guitar. Exploring these will lead to more words and terms like citole, cittern, mandore, and of course the lute . So many words to explore. I’m going to look into the gittern first, or maybe the kithara. This is so open ended.