The phrase "permeate region" can mean a geographical area that is saturated or filled with a particular substance or element. There are several synonyms for this phrase, such as "suffuse district," "imbue locale," "saturation zone," and "infuse territory." These terms also suggest an area that is thoroughly permeated by a substance or element. Additionally, other words that can be used in place of "permeate" include "invade," "penetrate," "infest," and "soak." When combined with words like "region" or "locale," these terms convey the idea of a space that is wholly infused with a particular substance or element.