Disreputable means not respectable in character, behaviour or appearance. You would not want to be seen with it.
It covers people, places and objects with equal ease, so a disreputable character, a disreputable pub and a disreputable old hat are all standard, and the last of those is affectionate. That range is the fun of the word, since applied to clothing it is fond and applied to a person it is a warning. The noun behind it is repute, and reputable is the positive form.
1adjectivedisreputableNot respectable in character or appearance.
“He wore the same disreputable jacket for twenty years.”
From dis- + reputable.
Etymology from Wiktionary, CC BY-SA