Which of the following terms describes a localized area of skin discoloration larger than a macule?

The term that describes a localized area of skin discoloration larger than a macule is a patch. A macule is defined as a flat, distinct, discolored area of skin that is less than 1 centimeter in diameter. In contrast, a patch is similar in appearance but is larger than 1 centimeter. Patches can be various colors and may be associated with a variety of skin conditions.

The other terms do not accurately describe skin discoloration in the same manner. A bump typically refers to a raised area on the skin, rather than a flat discolored area. A vein is not a term used for skin discoloration; it refers to blood vessels beneath the skin that may sometimes be visible but do not constitute a change in the skin's color. A scar indicates a mark left on the skin after healing from an injury, which also does not describe just a localized area of discoloration. Therefore, patch is the appropriate term for this context.