rutilant UK /ˈɹuːtɪl(ə)nt/US /ˈɹutələnt/ adjective1 •(literary) Shining or glowing with a red colour or light.Thy Candour, which the Opticks Quondam drew, / And o'er the Visible Ideas rang'd, / Was by the Gore of that Lewd Goddess chang'd / To Rutilant Purpureous Sanguin Hue. — 1707 formsmore rutilant · most rutilant