affixation 1. The addition of a prefix, suffix, or infix to a word in order to create a new word or an inflected form of a word. 2. The formation of a word by means of an affix. 3. The result of adding an affix to a root word. 4. The act of attaching or affixing something. Found on http://www.wordinfo.info/words/index/info/view_unit/3376/