Bring about the death, defeat, or ruin of, as in He swore he'd do for him. This usage is often put in the passive voice (see done for). [First half of 1700s]
Care or provide for, take care of, as in They decided to hire a housekeeper to do for Grandmother. This usage today is more common in Britain than in America. [Early 1500s]
Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.