How is a word defined?

A word is defined as a group of sounds put together in a meaningful unit. This definition highlights the essential nature of a word, which is that it conveys specific meaning through its combination of phonemes or sounds. Words function as the building blocks of language, enabling communication and the expression of thoughts, ideas, or emotions. They are not just random arrangements of letters; instead, they adhere to the phonological and morphological rules of a language, allowing them to be recognized and understood by speakers and listeners.

In contrast, the other options describe concepts that either do not align with the traditional definition of a word or refer to broader linguistic elements. While a phrase may convey a complete thought, it typically consists of multiple words rather than a single word. Similarly, an expression that represents an idea may encompass larger structures too, such as sentences or idioms, rather than isolating the concept to the confines of what a word is. Thus, the correct focus on the auditory and semantic aspect in the definition of a word is paramount to understanding its role in language.