The municipality (originally the parish) is named after the old
Jevnaker farm (
Old Norse:
Jafnakr), since the first church was built here. The first element is
jafn which means "even" or "flat" and the last element is
akr which means "
field" or "
acre". Prior to 1889, the name was written
"Jævnaker". The
coat-of-arms is from modern times, granted in 1983. The arms show three silver-colored
glasses, since
glassblowing has been a long tradition and industry in the municipality (see
Hadeland Glassverk). The red colour of the background was also chosen as the colour of the glass when hot. ==Geography==