The word "more coriaceous" refers to having a tough, leathery, and thick texture. The antonyms of this word could include soft, delicate, and thin. Other antonyms could be flexible, pliable, and malleable. These words provide a stark contrast to the rigidity and inflexibility associated with coriaceous materials. Additionally, antonyms like tender, gentle, and fragile describe materials or objects that are easy to bend, break, or damage. Overall, using antonyms of "more coriaceous" can help convey a sense of pliability or delicacy, creating a more nuanced description of the object or material in question.