The noun satiety means a state of fullness. Eating a huge, delicious meal will give you a satisfying feeling of satiety.
You don't often hear people using the word satiety in casual conversation. It's more often a technical term used by nutrition experts when they discuss the diet issues of populations or individual patients. Satiety is a state of being completely full, but the related adjective satiated is much more commonly used to describe someone who has eaten enough. The Latin root of satiety is satis, which means "enough."