Douglas Harper's Etymology Dictionary
claustration
1863, "act of shutting up in a cloister," as if from a noun of action formed in Latin from Latin claustrare, from claustrum (see cloister).
Wiktionary
claustration
n. 1 Shutting up or enclose, usually referring to a religious cloister. 2 A method used by emperors to keep their harems and to guarantee their virginity.
Usage examples of "claustration".
I was less sad than usual because the melancholy of her expression, the sort of claustration which the startling hue of her gown set between her and the rest of the world, made her seem somehow lonely and unhappy, apd this comforted me.