se·ri·ous·ly / ˈsi(ə)rēəslē/ • adv. 1. in a solemn or considered manner: the doctor looked seriously at him.2. with earnest intent; not lightly or superficially: I seriously considered canceling my subscription. ∎ really or sincerely (used esp. to indicate a response of surprise or shock): do you seriously believe that I would jeopardize my career by such acts? ∎ used to add sincerity to a statement that is to follow, esp. after a facetious exchange of remarks: seriously though, shortcuts rarely work. ∎ inf. used to indicate surprise at what someone has said and to check whether they really meant it: “I'm dying to know.” “Seriously?” “Of course.”3. to a degree that is significant or worrying because of possible danger or risk: the amount of fat you eat can seriously affect your health | three men are seriously ill in the hospital. 4. inf. very: he was seriously rich I drove to the station in a seriously bad mood.PHRASES: take someone/something seriously regard someone or something as important and worthy of attention.