胄

A phono-semantic compound consisting of:

肉 (月) — semantic component indicating body or lineage;

由 — phonetic component supplying the sound (주 / zhòu).

The component 由 functions as the phonetic element, as seen in characters like 宙 and 紬, which also have the reading 주.

The original meaning related to lineage or descendants connected to the body or bloodline.

Originally two different characters existed:

胄 — descendant; offspring

冑 — helmet

In the small seal script (說文解字):

胄 = 由 + 月 (肉)

冑 = 由 + 冃 (head covering)

During the development of regular script, the shapes 月 (derived from 肉) and 冃 became visually similar, leading to confusion.

As a result, 胄 began to be used for both meanings.

Semantic development:

- bloodline or descendant;

- noble offspring;

- helmet (due to graphic confusion with 冑).

후예 (後胄) — descendant

귀주 (貴胄) — noble descendant

왕주 (王胄) — royal descendant

These expressions emphasize noble lineage or ancestry.

胄 emphasizes noble lineage or aristocratic descent.

Related characters:

冑 — helmet (original character)

裔 — descendant

孫 — grandchild; descendant

族 — clan

The confusion between 胄 and 冑 is a well-known example of graphic convergence in Chinese character history.