What is the basic word element that identifies central meaning of a word?

The basic word element that identifies the central meaning of a word is called the root word. A root word is the core part of a word from which other words can be formed by adding prefixes, suffixes, or both. The root word carries the main semantic meaning of the word, while the prefixes and suffixes modify or extend the meaning. For example, in the word "unbreakable," the root word is "break." The prefix "un-" negates the meaning of the root word, making the word mean "not breakable" or "resistant to breaking."