What is the term for a comprehensive compilation of words used in a language?

The term "lexicon" refers to the complete collection of words and their meanings within a particular language. It serves as a linguistic inventory that includes not only the vocabulary but also information about words—such as their meanings, derivatives, and usages. In essence, the lexicon acts as a mental dictionary for speakers of the language, enabling them to understand and produce appropriate words in various contexts.

Phonology is the study of the sound systems within languages and how sounds function, which does not encompass the words themselves. A dialect pertains to specific variations of a language that arise from regional or social influences, often characterized by distinct vocabulary, pronunciation, and grammar. Syntax, on the other hand, involves the rules and principles that govern the structure of sentences, including how words combine to form grammatically correct sentences. Each of these terms relates to different aspects of language and linguistics, but only "lexicon" specifically refers to the complete set of words used in a language.