Definitions

1. noun

a mythical ogre, especially one that is green and ugly, often depicted as a large, grotesque, and grumpy creature

“In the movie Shrek, the titular character is a lovable ogre who befriends a talking donkey.”

2. verb

to be or become ugly or repulsive

“After eating the spoiled food, John started to shrek and ran to the bathroom to vomit.”