亡国 (conquered nation / wángguó) can be translated as “vanished country” or “a state heading for destruction/downfall.” It’s generally used to describe when an outside power has defeated a nation in war, either wiping it out or causing it to lose its independence. Examples include the overthrow of the Hawaiian Kingdom by the U.S., the conquering of the First Persian Empire by Alexander the Great, and the subjugation of the Korean Empire by Imperial Japan in 1910. It is also the Chinese title of a somewhat controversial 2005 Japanese action thriller Aegis (Bôkoku no îjisu).
Why it is blocked: Perhaps the term is used by Tibetans or citizens in Xinjiang to describe Chinese control of their provinces? Or maybe netizens use it to insult the future state of China or to describe instances of China appearing to bow to outside/American influences? The term popped up in several news reports related to China’s recent dispute with the Philippines in the South China Seas. However, it is also widely used in an apolitical manner, often to describe something that is extinct or a situation wherein someone is suppressing another.