Definition of across preposition from the Oxford Advanced American Dictionary
across
preposition
/əˈkrɔs/
1from one side to the other side of somethingHe walked across the field.I drew a line across the page.A grin spread across her face.Where's the nearest bridge across the river?2on the other side of somethingThere's a bank right across the street.3on or over a part of the bodyHe hit him across the face.It's too tight across the back.4in every part of a place, group of people, etc.synonymthroughoutHer family is scattered across the country.This view is common across all sections of the community.