Which word would you use to describe something as unnecessary or more than enough?

The term that conveys the idea of being unnecessary or excessive is "superfluous." This word specifically refers to something that exceeds what is sufficient or necessary, indicating an abundance that is not required. For instance, in a sentence like "The report included superfluous details," it emphasizes that certain details were present but not needed for the understanding of the main points.

The other choices do not align with this meaning. "Supercilious" describes someone who behaves or looks as though they think they are superior to others, which is a different concept entirely. "Brevity" refers to the quality of being brief and concise, often valued in communication, while "sullen" denotes a gloomy or sulky disposition. Each of these terms carries its own unique meaning that does not relate to the idea of excessiveness or unnecessary attributes. Therefore, "superfluous" is the precise term to describe something that is more than enough or unnecessary.