(名詞) 孤獨或獨居 (solitude) 的狀態或情況。

Entering a relationship with a romantic "life partner," commonly through marriage, is considered a significant social marker, denoting full adulthood and providing universally recognized social reasons, which do not meet with requests for further explanation. Some groups may accord this status only to marriage, others more broadly to cohabitants; but it is an evaluative social classification that friendships or, even more so, solitudinousness rarely breach.
—Elizabeth Brake, Minimizing Marriage, Oxford University Press, March 15, 2012

Van Vogt was the first Canadian sf writer of real importance, and it is arguable that a Canadian solitudinousness colours his work throughout.
—"van Vogt, A E," The Encyclopedia of Science Fiction, October 14, 2014