向かい
むかい · mukai · JLPT N3 · noun
across
向かい is the noun form of 向かう (to face): the spot facing you
向 means direction or facing. Add かう and you get the verb 向かう, to face or head toward. Drop it to the noun 向かい and it means the thing that faces you: the house across the street is お向かい.
向 — roof 宀 + mouth 口
Originally a pictograph of a house with a north-facing window, showing an opening in a wall under a roof. The early meaning was 'north window,' which extended to 'the direction something faces,' then broadly to 'toward' or 'direction.' The modern shape simplified the window into 口.