mild·ly / ˈmīldlē/ • adv. in a mild manner, in particular without anger or severity. ∎ not seriously or dangerously: he had suffered mildly from the illness since he was 23. ∎ to a slight extent: he kept his voice mildly curious. PHRASES: to put it mildly (or putting it mildly) used to imply that the reality is more extreme, usually worse: the proposals were, to put it mildly, unpopular.