place
There is no known synonym for the term cultural region. It does not have a known antonym either. A region is either cultural or it is not.
It could be viewd as a synonym for country, county, continent, state, area, etc.
surroundings, territory, environment, district, locality, region, nearness
A synonym for area is range.
acres, agricultural region, alkali flat, alluvial plain
suburb,countryside
Sol isn't a synonym for light. I personally like "electromagnetic radiation in the 390-750 nm region."
An area is an amount of space that can be big or small. A synonym for area is region.
near close surrounding, about, enclosing, encompassing, framing, encircling, approximately, about, nearly, close to, roughly, just about, in the region of
A synonym for a very large area within a continent is a region.
Range, scope, region, or degree is the synonym of extent.
autarky, bimetallism, clannishness, clanship, cliqueyness, cliquishness, cliquism, denominationalism, economic