重

Originally, the character was made by writing 東 under 人, but in the process of the Large Seal Script formation, 東 was changed into the form of 里, and the 人 on top was also modified, resulting in its present form.

One theory—generally accepted—is that the character is a pictophonetic compound combining the shape of a person (人) with the shape of a tied load, expressing “a person carrying a heavy burden,” hence the meaning “heavy.”

Another interpretation is that it is a phono-semantic compound, in which the “person carrying a load” represents the meaning, while the sound comes from 東 (pronounced dong, which later shifted to jung). Naver Dictionary adopts this latter view.

The meaning “to overlap” is explained in the Okpyeon dictionary as originally belonging to 緟 (jong, “to add, repeat, overlap,” U+7DDF), but later being replaced with 重. The classical scholar Shirakawa Shizuka also held this view. Shirakawa further explained the meaning based on 𤕌 (U+2454C), an earlier form of 緟 found in bronze inscriptions: a skein of thread (𤔔) placed into a sack (東—in bronze script similar to 束 “to tie” or 橐 “bag”), then repeatedly put into a cauldron (田) for dyeing. Thus, its original meaning was “to dye,” and from this came the extended meaning “to repeat, to overlap.” Later, this was replaced by the phono-semantic compound 緟, which was further simplified so that only its phonetic component 重 remained in use.

Common in Sino-Korean compounds such as:

중요(重要) “important,”

중량(重量) “weight,”

중복(重複) “overlap.”

In native usage, -중(重) functions as a bound noun meaning “layer, fold, duplication.” For example, 이중(二重) “double,” 삼중(三重) “triple.”

Perhaps because of this distinct origin, outside Korea the pronunciations differ depending on meaning. For example, in Standard Chinese, when used with the meaning “heavy” or “important,” it is pronounced [zhòng]; but when meaning “to overlap,” it is pronounced [chóng].

Originally in Japanese too, it should be read じゅう (jū) for “heavy, important,” and ちょう (chō) for “to overlap.” However, mistaken readings have become established as common pronunciations. For instance, 重複 (repetition) should correctly be read ちょうふく (chōfuku), but many people incorrectly read it as じゅうふく (jūfuku).

Meanwhile, the bound noun 중 (重) meaning “layer, fold” is read じゅう (jū) in Japanese.