㴾

㴾 is a variant form of 渤, read bó.

The two have counted as the same word for a long time: the Jiyun, a rime dictionary — a book that sorted characters by pronunciation — compiled in 1037–1039, already gives 㴾 as another writing of 渤, and later character dictionaries repeat the equation.

Structurally it is a sound–meaning compound: the water sign 氵 marks the meaning field, and the right side belongs to the 勃 sound-family that supplies the reading bó. The word it writes is old — the sea name 渤海, also spelled 勃海 in early texts, went on to name a Han-dynasty commandery and, after a Tang investiture in 713, the northeastern kingdom of Bohai, called Balhae in Korean.

Use 渤 when clarity matters

Choosing 㴾 tells a reader that the spelling itself is the point — you are reproducing an old dictionary entry, a manuscript, or a character list. A reader who knows standard 渤 decodes it at once; everyone else just sees an unfamiliar glyph.

So: 㴾 for faithful quotation and character history; 渤 — or the full name 渤海 — whenever recognition matters.