 The municipality (originally the parish) is named after the old farm Sem (Norse "Sæmr" - a compressed form of "*Sæheimr"), since the first church was built there.The first element is "sær" m 'sea, water' (here the Tønsberg fjord), the last element is "heimr" m 'farm; home'.Doug Jarrett

Douglas William Jarrett (April 22, 1944 – February 10, 2014) was a Canadian ice hockey defenceman, who played in the National Hockey League (NHL) with the Chicago Black Hawks and New York Rangers.