Pellucidness refers to a level of clarity and transparency that allows ease in understanding or perceiving. Its antonyms, therefore, would describe qualities that hinder comprehension and visibility. Some possible antonyms for pellucidness include opacity, fuzziness, obscurity, murkiness, cloudiness, ambiguity, and indistinctness. Opacity refers to an ability to block or hide light, making it difficult to see through an object or material. Fuzziness denotes a lack of sharpness, causing images or ideas to appear unclear or blurred. Obscurity and murkiness imply a level of depth or complexity that hinders comprehension or visibility. Cloudiness suggests the presence of something that interferes with clear perception, while ambiguity and indistinctness refer to a lack of clarity or definition.