a prefix meaning “within, in,” occurring in loanwords from Greek: energy; enthusiasm.

For example, the common suffix “-en” can mean “made from” or “become.” But notably, these different meanings also result in entirely different parts of speech. It can be used in adjectives that describe what something is made from (i.e. “earthen”).

The prefix en- means ''in'' or ''within,'' and it's generally added to a word to make it a verb. In the word encode, the base of the word is code, which is a series of symbols, letters, or other words that are used to make the message a secret.

1. : the width of a piece of type half the width of an em. 2. : the letter n. en-