1.
Something that is ~ is so bad or unpleasant that it shocks you.
They have been living under the most ~ conditions for two months.
= dreadful
ADJ
~ly
He says that he understands why they behaved so ~ly...
ADV
2.
You can use ~ to emphasize that something is very great or severe.
I developed an ~ headache.
ADJ emphasis
~ly
It’s been an ~ly busy morning.
ADV
3.
see also appal