Learner's definition of MILD
[more mild; most mild]
1 : gentle in nature or behavior 2 a : not strong in action or effect
b : not strong or harsh in taste c : not strongly felt
a mild drug/detergent
mild [=gentle] soap
3 a : not harsh or severe
b : not too hot or too cold: pleasantly warm
She has a mild case of the flu.
a mild headache/fever
He suffered a mild concussion/heart attack.
a mild reprimand, not a stern one
He's mildly [=slightly, somewhat] interested in politics.
It's a mildly amusing comedy.
He has been mildly criticized by a few former colleagues.
She was upset, to put it mildly. [=she was extremely upset]
He is, to put it mildly, a demanding boss. [=he is a very demanding boss]