unstable: anxious because of the inability to get what one wants

instability: the state of anxiety caused by the inability to get what one wants

Xiamen, Amoy (a subprovincial city in Fujian, in southeastern China)

Amoy, Xiamen (a subprovincial city in Fujian, in southeastern China)

Kyūjitai form of 黄門

speciality; specialty; subject of study; expert

a back gate / (figuratively) the anus, as a homophone for 肛門 and in contrast to 前門 (zenmon, “front gate”, figurative for vagina)

sluicegate, lock gate

(taxonomy) subphylum

a triumphal arch; in particular, the Arc de Triomphe in Paris