Lapidarian is derived from the Latin word "lapis", meaning stone. It is an adjective that describes something that is finely carved, polished or presented with great attention to detail. The antonyms for "most lapidarian" would be words that describe something that is rough, crude, or poorly executed.
The words that come to mind are unpolished, unrefined, coarse, and rustic. These words are the opposite of lapidarian because they suggest a lack of attention to detail and craftsmanship. Something that is unpolished, for instance, would be uneven, rough or rugged. Similarly, something that is unrefined would be crude, unfinished or raw.
Overall, antonyms for "most lapidarian" paint a picture of something that is the opposite of elegant, sophisticated, and precise.