中枢
ちゅうすう · chuusuu · JLPT N1 · noun
center
🚪 中 = middle + 枢 = door pivot: the middle pivot everything turns on
枢 is the pivot pin a door swings on. So 中枢 is the central pivot that a system turns on, its nucleus and mainstay.
中 — vertical stroke 丨 through enclosure 口
Pictograph of a banner or pole piercing the center of a target or territory, depicting the idea of 'middle' or 'center'. The horizontal frame represents boundaries, and the vertical line marks the central axis. The meaning extended from spatial center to 'middle, central, China' (中国, the Middle Kingdom).