The word "most pictoric" refers to something that is highly visual, vivid, or picturesque. The antonym of this word would be something that is less visual, less vivid, or less picturesque. Some possible antonyms for "most pictoric" include dull, bland, unremarkable, uninteresting, drab, or prosaic. These words suggest that the subject is not particularly visually stimulating or attractive, and may even be considered boring or uninspiring. Alternatively, a more positive antonym for "most pictoric" could be "abstract," which implies that the subject is not necessarily visually realistic or representational, but rather focuses on shape, color, form, and other artistic elements.