共同
gòngtóng · HSK 3
joint
🤝 共 (together) + 同 (same) = common, joint, shared
共 means together or shared; 同 means same or alike. Stacked, 共同 names what two or more parties hold in common — a joint effort, a shared goal, a common interest.
共 — 两手 (廾) holding up an object
共 originally depicted two hands raised together, lifting or offering something jointly. The ancient form showed a vessel or object held up by paired hands, conveying shared action. From 'lifting together' it shifted to mean 'together,' 'common,' or 'share.'
同 — 冂 enclosure + 一 + 口 mouth
Originally depicted multiple mouths gathered under one cover or enclosure, suggesting people speaking together in agreement. From this image of voices joining, it came to mean 'same,' 'together,' or 'alike.' The shared cover symbolizes unity.