宣

Phono-semantic compound:

宀 (갓머리, “roof”) — semantic, denotes something happening inside a building or hall.

亘 (펼 선, “to extend, span”) — phonetic, provides sound 선.

Thus, the idea is of spreading/announcing under a roof, i.e., making a declaration publicly.

宣言 (선언) — declaration, proclamation

宣傳 (선전) — publicity, propaganda

宣敎 (선교) — missionary work, spreading a religion

宣佈 (선포) — to announce, make public

In ancient contexts, 宣 was associated with royal or official announcements made in a hall.

Related in meaning to terms of proclamation and dissemination, often used in political or religious contexts.