He is, 'to put it mildly', a demanding boss. [=he is a very demanding boss]
He's 'mildly' [='slightly, somewhat'] interested in politics.
She was upset, 'to put it mildly'. [=she was extremely upset]
(..) What!? You didn't have Ben threaten him? Or, or, or hurt them? I just asked Ben, if he could talk to him. You tried speaking to him. but you're so mild mannered! I thought Ben would tell him if he didn't start behaving himself... What Evelyn? He would start breaking his legs? (..)2016 Café Society