mildly

/ˈmaɪld.li/

adv. 温和地，和善地;适度地，略微地

I was mildly surprised to see him here.

在这里看到他令我略感惊讶。

That would be a mildly arrogant viewpoint.

这个观点或许略微有些自大。

put it mildly

说得委婉些; 说得好听一点

used for saying that something is much more extreme than your words suggest

保守地说;说得好听(或委婉)一点

It has been a remarkable day, to put it mildly.

说得委婉一点，这是不寻常的一天。