The prefix "en" means to cause a person or thing to be in the state, condition or place defined by the stem word. An example of the prefix "en" in use is found in the word "entomb," which means place a person into a tomb.
Other examples of the prefix "en" in use are found in words that include endear, encourage and encircle. The prefix "en" is thought to have been introduced into the English language via words borrowed from French, so-called loanwords. The ultimate root of the prefix "en" is Latin. "En" became used in the English language during the Middle Ages.