The term "slicked up" often implies a polished, groomed, or sophisticated appearance or demeanor. Its antonyms, on the other hand, convey the opposite idea. Words such as disheveled, unkempt, messy, shabby, or scruffy denote a lack of neatness or tidiness. Similarly, informal, casual, or laid-back describe a relaxed, unconcerned, or unpretentious style rather than one that is meticulously orchestrated for effect. Less-common antonyms for "slicked up" might include stuffy, dull, or coarse, which suggest an absence of elegance, refinement, or grace rather than the disorderliness or informality conveyed by other antonyms.