What is "westergeest"

Westergeest ( Low Saxon: Westergaist) is a village in Kollumerland c.a. in the province of Friesland, the Netherlands. It has a population of around 637. It is located on a slight hill ( geest) left by a glacier about a meter above the surrounding land, with the oldest building being the church, built around 1130. There is a restored windmill north of the village, De Beintemapoldermolen. The village is often nicknamed Foestrum though the origin of this name is unclear. It is popularly said to be derived from the name of a goddess who was worshipped here in a temple before the arrival of Christianity, however there is no proof of this theory.