I hope I will be released from the hospital soon.
Time to retreat from the institution. Basically, you are leaving an institution, particularly institutions like hospitals, asylums, etc. When you are leaving one of these places, it means you are to be discharged.
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.