加

Originally a compound ideogramc depicting 力 (strength) combined with 口 (mouth) — interpreted as “exerting strength with the mouth”, or “to voice encouragement or apply effort.”

Another ancient variant replaces 口 with 龠 (flute 약), suggesting using breath and strength together, hence to exert oneself or amplify sound, symbolically “to augment.”

From this core meaning of “applying or adding force,” the semantic field expanded to increase, supplement, praise, or participate.

It is sometimes etymologically connected to 嘉 (to praise, commend), as both carry the notion of approval or enhancement.

더할 가 (加) — to add, to increase

가중 (加重) — to intensify, aggravate

가속 (加速) — to accelerate

참가 (參加) — to participate

가산 (加算) — to compute by addition

가공 (加工) — to process, refine

Figuratively: to apply a penalty or blessing (형벌을 가하다, 은혜를 가하다).

In East Asian thought, 加 often conveys not only numerical addition but strengthening of quality or virtue — the idea that augmentation is progress.

In Confucian usage, to 加禮 (add propriety) or 加德 (add virtue) signifies moral refinement through conscious effort.

In modern idiom, 加油 (add oil) in Chinese and 파이팅! (fighting!) in Korean both descend from the same metaphor — to add energy or fuel to one’s endeavor.