(manner) In a simple way or state; considered in or by itself; without addition; alone.
(manner) Plainly; without art or subtlety
(manner) Weakly; foolishly; stupidly.
(focus) Merely; solely.
I was simply asking a question.
(degree) absolutely, positively.
That was a simply wonderful dessert.
Frankly.
Simply, he just fired you.