Affix

1. affix (noun, verb)

2. affixes, affixed, affixing, affixment, affixer, affixiable

3.affix: n. a. A word element, such as a prefix or suffix, that is attached to a base, stem, or root. b. Something that is attached joined, or added. v. a. To secure (an object) to another; attach b. To place at the end. (Vocabulary for Achievement)

4. Affixes can often tell a lot about the word; for example, words with prefixes in-, un- or im- often imply the opposite of the root, and the suffixes -ment, -ance, or - tion, are usually the noun form of the root.
5. John Hancock's signature is one of the most famous affixments on the Declaration of Independence.