A tool that does to words what a food processor...Sorry...
Software used to generate, edit, and format text-based documents. The most popular examples--Microsoft Word, Corel WordPerfect, etc.--can also track annotations, auto-generate web pages, feed the cat, and fill your entire hard drive.
Also, a person used to type words into a word processor until that person develops carpal tunnel syndrome, at which point he or she is thrown away and replaced.