From Longman Dictionary of Contemporary Englishlow-gradeˈlow-grade adjective [only before noun] 1 not very good in quality inexpensive low-grade paper2 a low-grade medical condition is not very serious a low-grade feverFrom Longman Business Dictionarylow-gradeˈlow-grade adjective1of low quality or a poor standardWomen were forced into part-time low-grade jobs.low-grade steel2FINANCE low-grade bonds, loans etc have a high risk of not being repaidlow-grade debt issued by lower-rated companies in the junk bond market