Which term describes someone who expresses themselves clearly and effectively?

The term that best describes someone who expresses themselves clearly and effectively is "eloquent." Eloquent speakers or writers have the ability to convey their thoughts and emotions with clarity, fluency, and persuasive power. They often use language that is both articulate and expressive, making their communication impactful and memorable.

In contrast, "cogent" refers specifically to arguments or reasoning that are clear, logical, and convincing; while it may overlap in meaning with "eloquent," it does not necessarily encompass the broader concept of effective expression in general communication.

The term "circumspect" describes a person who is cautious and considers all circumstances and possible consequences, but it does not directly relate to the clarity or effectiveness of expression.

"Discretion" refers to the quality of being careful about what one does or says, or the ability to make responsible decisions, and it does not specifically address clarity in expression.

Therefore, "eloquent" is the most fitting term to describe someone who can convey their thoughts clearly and effectively.