Looking old, worn, and not well cared for; or treating someone meanly or unfairly.
From the word 'shab' meaning scab or mange (a skin disease in animals), suggesting something that looks diseased or deteriorated. The word emerged in the 1600s-1700s to describe worn clothing and buildings.
Victorian England had a whole social category called 'shabby genteel' for people who maintained proper manners but wore shabby clothes—they cared so much about appearing respectable that shabby became a mark of pride for struggling middle-class families.
Complete word intelligence in one call. Free tier — 50 lookups/day.