庸

A phono-semantic compound:

庚 — semantic element, associated with order, regulation, or structured activity

用 — phonetic element, giving the sound 용 (yong) and reinforcing the meaning to use

Originally, 庸 conveyed the idea of putting something to proper use, which later expanded to mean service rendered, and eventually what is commonly used, hence ordinary.

Meaning development:

- to use / to employ;

- service, merit (what is produced by proper use);

- commonly used;

- ordinary, mediocre;

This semantic shift explains why the character can carry both neutral-positive and negative connotations, depending on context.

중용 (中庸) — the Doctrine of the Mean

평용 (平庸) — mediocrity; being ordinary

용인 (庸人) — an ordinary or mediocre person

용재 (庸才) — mediocre talent

In classical texts, 庸 often refers to employing people or things appropriately, or to the merit gained through service:

庸之以治 — use it to govern

庸功 — meritorious service

中庸 (Doctrine of the Mean) — one of the most important uses of 庸 is in 中庸, a Confucian classic traditionally attributed to Zisi (子思).

Here, 庸 does not mean “mediocre” but rather "properly applied, constant, fitting in everyday life."

Thus, 中庸 emphasizes balanced, appropriate conduct, not dullness.

In later Chinese and Korean usage, 庸 increasingly took on a pejorative tone, especially in compounds like:

平庸 (mediocre)

庸才 (inferior talent)

This reflects a shift from “commonly applicable” to “unremarkable”.

Related characters:

用 — to use

常 — constant; ordinary

凡 — common; general

功 — merit; achievement