sterner adj. + Add to list US //ˈstɝnɝ// UK //stˈɜːnɐ// stern·er Synonyms Synonyms austereexactinggriminexorablerelentlesssternstrictunappeasableunforgivingunrelenting Idioms1 entry01made of sterner stuffstrong and determined (especially more so than someone else, to whom one is being compared).