proclaim, say, announce
宣 centers on making a formal or public statement: proclaiming, announcing, or saying something with authority.
宣 combines 宀 (roof) with 亘, which likely contributes the sound and suggests spreading or extending, giving the idea of a proclamation spreading under a roof or from an official place.
Under a roof 宀, a message spreads out like the extended shape of 亘: a public proclamation is announced.
For セン, imagine a town crier announcing a proclamation for one thousand (千, せん) people gathered under the roof: 千 -> セン.
publicity; advertisement; advertising; propaganda
declaration; proclamation; announcement
sentence; verdict; pronouncement
imperial order; imperial decree
oath; abjuration; pledge
declaration of war
carrying out (political) propaganda activity on the streets
missionary
religious mission; religious proclamation
oracle; revelation; divine message
to say; to be pleased to say
proclamation; dissemination; promulgation
oracle; revelation; divine message
global declaration
system declaration
system conformance statement
protocol implementation conformance statement; PICS
Potsdam Declaration (July 26, 1945 statement establishing the terms of a Japanese surrender)
marked section declaration
markup declaration