The word 宣传 is formed through the complementary combination of two characters, each contributing a key aspect of the overall concept. The first character, 宣, carries the core meaning of "to declare", "to announce", or "to spread openly". The second character, 传, means "to transmit", "to pass on", or "to circulate". When fused, they create a single term where 宣 provides the action of openly making something known and 传 adds the crucial dimension of actively disseminating and relaying that information to an audience, thus perfectly encapsulating the modern meaning of "to propagate" or "to conduct publicity".