Greitening
An extreme form of frightening. Originating the IB subject of Theory of Knowledge. Can be used to describe assessments or class periods in general, but is commonly also used outside class to describe truly fear-instilling things.
Person 1: Yoo, TOK class was stupid and abysmal again today.
Person 2: Sounds like it was very Greitening.
Person 2: Sounds like it was very Greitening.