sternly UK /ˈstɜːnli/US /ˈstɝnli/ adverb1 •In a stern manner.It was a historic night at Wembley Stadium that saw the European champions sternly tested by Copa America winners Brazil, but ended with the familiar sight of captain Leah Williamson lifting a trophy. — 2023 formsmore sternly · sternlier · most sternly · sternliest