What does "raiment" most nearly mean?

The term "raiment" refers to clothing or garments, which is why "attire" is the correct choice. In literature and common usage, "raiment" is often used to describe clothing in a somewhat formal or poetic context. This aligns perfectly with the definition of attire, which pertains to dress or garments that individuals wear.

The other options do not relate to clothing. "Brightness" refers to the quality of being bright, which pertains to light rather than clothing. "Tinge" refers to a slight coloring or shade, unrelated to the concept of attire. "Complication" denotes a difficulty or intricate situation, which does not connect to clothing or garments at all. Thus, "raiment" is best associated with attire, making that the most accurate answer.