Defining vocabulary can also be referred to as core vocabulary, key terms, or essential language. It is the set of words and phrases that are integral to understanding a particular subject or concept. Commonly used language, jargon, and technical terminology make up defining vocabulary, and it is an important aspect of effective communication and comprehension. Some other terms that could be used in place of defining vocabulary include foundational language, essential lexicon, and key vocabulary. Understanding and utilizing these synonyms can help to broaden our understanding of language and improve our ability to effectively communicate complex ideas and concepts.