Gjerdrum (Norwegian: [ˈjæ̀rdrʉm]) is a municipality in Akershus county, Norway. It is part of the traditional region of Romerike. Gjerdrum borders the municipalities of Nannestad, Nittedal, and Ullensaker, and Lillestrøm. The administrative centre of the municipality is the village of Ask. Name and coat of arms. The municipality (originally the parish) is named after the old Gjerdrum farm (Norse Gerðarvin). The first element is the genitive of a river name Gerð and the last element is vin 'meadow, pasture'.
https://en.wikipedia.org/wiki/Gjerdrum