"Crasser" is an adjective that denotes a lack of refinement or sophistication. When seeking synonyms for this word, numerous options present themselves. A synonym could be "coarser", which highlights a rougher or less polished demeanor. Another possibility is "vulgar", conveying a more unsophisticated or unrefined nature. "Brutish" can also be used, indicating a demeanor lacking in grace or manners. "Rude" is another synonym for "crasser", emphasizing a lack of consideration or civility in one's behavior. Overall, these synonyms offer alternative ways to express the concept of lacking refinement, highlighting the importance of choosing the most appropriate term based on context and desired level of intensity.