兼用
けんよう · kenyou · JLPT N1 · noun
multi-use
兼 — hand 又 holding two grain stalks 秝
兼 is an ideograph showing a hand (又) grasping two stalks of grain (秝) at once. The original meaning was 'to hold two things together,' which extended to 'combine,' 'simultaneously,' and 'both.' This sense of doubling up survives in modern compounds like 兼职 (hold a concurrent job).
用 — pictograph of a bucket or wooden pail
用 originally depicted a bucket or container, possibly a sacrificial vessel made of wood. Over time it was borrowed to mean 'to use' or 'employ,' losing its concrete object sense. The modern meaning 'use' has been standard since early classical Chinese.