galactic year
英[gəˈlæktɪk jə:]美[ɡəˈlæktɪk jɪr]
The galactic year, also known as a cosmic year, is the duration of time required for the Solar System to orbit once around the center of the Milky Way Galaxy.Cosmic Year, Fact Guru, University of Ottawa Estimates of the length of one orbit range from 225 to 250 million "terrestrial" years.