← BackshareGuesssolemnly/ˈsɑləmli/adverbIn a serious, sincere, and formal way, without humor or lightness.They walked solemnly through the memorial, heads bowed.The judge solemnly read the verdict to the courtroom.She solemnly promised to take care of her little brother.SynonymsseriouslyearnestlygravelyAntonymslightlyjokingly