The term 'pasture FIELD' is composed of two words: LEA, a three-letter word, and FIELD. LEA is an old English word meaning a grassy meadow or open land used for grazing animals. A pasture FIELD is an area of land that has been set aside for the purpose of grazing animals, such as cows, sheep, and horses. It is typically composed of grasses and other vegetation that provide food for the animals. The pasture FIELD is usually surrounded by a fence to keep the animals from wandering off.