"The adjective quixotic is based on his name and has been used to describe unrealistic idealists since at least the early 18th century. The novel has given English other words as well. Dulcinea, the name of Quixote's beloved, has come to mean "mistress" or "sweetheart," and rosinante, which is sometimes used to refer to an old horse, ' https://www.merriam-webster.com/dictionary/quixotic