Embox is a relatively uncommon word, meaning to place into a box or to enclose. Additionally, it can be used as a noun to describe a small box for holding letters or other small items. There are a variety of synonyms for this word, including encase, envelop, enclose, and contain. Some other options might include box up, package, wrap, or stuff. In certain contexts, encircle or surround might also be appropriate alternatives. Overall, while embox may not be a commonly used term, there are many other words available to convey the same basic meaning and function.