tonkotsu UK /tɒŋˈkɒtsuː/US /tɑŋˈkɑtsu/ noun2 •A Japanese broth made from pork marrow, typically served with ramen. •A Japanese tobacco-box.Tonkotsu are distinguished from inro in several ways. The tonkotsu is a container for tobacco; the inro, for medicines. — 1979