The lead actor got sick all of a sudden and we couldn't find another actor to fill in for him. It was such a nightmare.
I had a bad dream that I turned into a fat cat that couldn’t walk.
I heard you can make yourself have nightmares if you sleep with your arms folded across your chest, so I tried it and I had a dream that I was cleaning a toilet nonstop from morning to night.
A bad dream is also known as a nightmare. Ah! Noooooo!
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.