What refers to the practice of adding parts both before and after words, such as in the word enlighten?

The term that refers to the practice of adding parts both before and after a word is known as circumfixes. Circumfixes are unique in that they encompass both a prefix (a morpheme added to the beginning of a word) and a suffix (a morpheme added to the end of a word). In the case of the word "enlighten," the prefix "en-" and the suffix "-en" together contribute to the meaning of the root word "light," thus illustrating the concept of a circumfix. This method of word formation is less common than using single prefixes or suffixes but plays a significant role in certain languages and linguistic structures. Understanding circumfixes helps in grasping how different elements of language contribute to meaning through structural modification.