The antonyms for the word "most highly-seasoned" include bland, tasteless, mild, unappetizing, insipid, plain, flavorless, and unsavory. These words describe food that lacks seasoning or flavor, and may be unappealing to those who enjoy bold and robust flavors. While highly-seasoned food can be enjoyable, it may not be suitable for all tastes or dietary restrictions. Some dishes may require a lighter touch with seasonings or rely on natural flavors to shine through. Ultimately, the choice of seasoning depends on personal preference and the type of cuisine being prepared.