From Longman Dictionary of Contemporary Englishshoulder strapˈshoulder strap noun [countable] 1 DCCa long narrow piece of material on a dress or other piece of women’s clothing that goes over the shoulder2 DCa long narrow piece of material fixed to a bag etc so that you can carry it over your shoulder
Examples from the Corpus
shoulder strap• Forward seat belts each comprised a two-piece lap strap, fastened by a buckle, and an inertial reel diagonal shoulder strap. 