Slipshod, slovenly, unkempt, disheveled, sloppy are comparable when applied to persons and their appearance or to their mental and manual processes, performances, or products, and mean manifesting conspicuous negligence or carelessness.
Slipshod implies an easygoing tolerance of details that are inaccurate, incongruous, or lacking in precision, or careless indifference to the niceties of technique or to qualities that make for perfection (as thoroughness, soundness, and fastidiousness).
Slovenly , a stronger term than slipshod , implies laziness and disorderliness which is evident throughout and is not merely a matter of detail. The term may be used of a person or his appearance and imply diametrical opposition to neat or tidy or it may be applied to processes, technique, or workmanship without significant change in value.
Unkempt is applied usually to something that requires to be kept in order if a favorable impression is to be produced. It implies extreme negligence amounting to neglect.
Disheveled is more likely to describe a temporary state of ruffled disorder or disarray following intense effort (as in doing something or coping with some emergency) or in extended application a lack of normal planned orderliness (as of concept or development).
Sloppy implies a general effect of looseness and of spilling over. When applied to a person or his appearance it usually suggests loose, ill-fitting, unpressed garments, but it often also carries connotations of slovenliness.
When applied to ideas or their expression, style, or manners or to a work or its workmanship, the word usually suggests a lack of control and precision or of confinement within proper limits, manifested in incoherency, emotional excess, or formlessness.