【Slatternly】 , 【dowdy】 ,  【frowzy】 ,  【blowsy】  can all mean deficient in neatness, freshness, or smartness, especially in dress or appearance.

【Slatternly】 stresses notions of slovenliness, unkemptness, and sordidness.

【Dowdy】 is likely to imply a complete lack of taste typically marked by a blend of something untidy, drab, or tawdry.

【Frowzy】 suggests a lazy lack of neatness, order, and cleanliness, but  【frowzy】 also may apply to a natural and not unwholesome disorder or it may suggest drab misery and squalor as an inevitable result of circumstances.

【Blowsy】 implies dishevelment or disorder to which is often added a notion of crudity or coarseness or grossness.