Affixial refers to the act of adding an affix to a word, which changes its meaning or grammatical function. Synonyms for affixial include derivational, suffixal, prefixal, postfixal, and functional. Derivational refers to the creation of a new word from an existing one using an affix. Suffixal pertains to a suffix being added to the end of a word. Prefixal is when a prefix is added to the beginning of a word. Postfixal is when an affix is added to the end of a word without changing its syntactic category. Functional affixation is when an affix is added to a word to indicate its grammatical function in a sentence.