Who is defined as someone who purchases a good or service with the intent to use it?

The term that best fits the definition of someone who purchases a good or service with the intent to use it is "consumer." This term specifically refers to the end user of a product or service, emphasizing that the individual not only buys the good but intends to utilize it for personal or household purposes.

In contrast, the term "customer" typically describes someone who purchases goods and services, but it may not always imply that the individual intends to use them. For example, a customer could be buying a gift for someone else, not necessarily for their own consumption. The term "buyer" is often used interchangeably with "customer," but it can imply a broader context, including anyone engaged in a purchase transaction, regardless of the intended use. "Trader" usually indicates someone who exchanges goods or services, often within a business context, rather than focusing on individual consumption.

Therefore, the distinction lies in the focus on usage intention. "Consumer" clearly encapsulates the idea of actual usage after purchase, making it the most appropriate choice in the context provided.