In reference to a stage of a medieval siege, where the attackers may seize the outer layer of defenses, but not the inner keep or citadel. At this point the attackers may themselves become besieged within the walls by a relieving army, with the original inhabitants of the fortress still stuck inside.
"Many Americansfeel Citadelled by political parties that no longer represent their interests."
Someone who jumps from one relationship immediately into another one.
Serial monogamists can not stand to be alone and often suffer from vast commitment and insecurity issues.
Because they jump into relationships immediately after the previous one has ended, serial monogamists typically don't take the time to reflect on their behavior or why their previous relationships failed; thus, they end up making the same relationship mistakes over and over again.
Person 1: Damn, Dustin already has a new girlfriend?! It's only been two weeks since he broke up with his fiance! I think he's a sociopath.