lackluster UK /ˈlæklʌstə/US /ˈlæklʌstɚ/adjective 3noun 2forms 3 adjective3 •Lacking brilliance or intelligence. •Having no shine or luster; dull.A faded, and an ancient dragon he was; and many a wintry storm of rain, snow, sleet, and hail, had changed his colour from a gaudy blue to a faint lack-lustre shade of gray. — 1842 •(figurative) Not exceptional; not worthy of special merit, attention, or interest; having no vitality.The actor gave a lackluster performance in his latest film. noun2 •Lack of brightness or points of interest. •A person or thing of no particular brilliance or intelligence. formslacklusters · more lackluster · most lackluster