Today was the worst day ever.
The worst case scenario is that I just have to sleep less and work, but it'll be okay.
"My car was stolen last night." "Oh, no! That’s the worst!"
The most bad is the worst. At least all there is is up now, right?
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.