noun
lonely and helpless; without anyone to rely on
A yojijukugo describing a state of utter isolation, originally referring to widowers, widows, orphans, and the childless, but now used more broadly for those with no one to depend on.
彼は鰥寡孤独の身の上で、頼れる親族もいなかった。
He was utterly alone, with no relatives to rely on.
戦争で家族を失い、鰥寡孤独の状態になった。
Having lost his family in the war, he was left completely alone and helpless.