noun
feeling of tragic heroism; grim resolve; sense of determination
A solemn, often dramatic feeling of facing a difficult or hopeless situation with courage and resolve. Common in descriptions of historical or fictional sacrifice.
特攻隊の遺書には悲壮感が漂っている。
The suicide pilots' farewell letters are filled with a feeling of tragic heroism.
彼は悲壮感を漂わせながら、最後の戦いに臨んだ
With a sense of grim resolve, he faced the final battle.
覚悟 is a more general term for readiness or preparedness for something difficult, without the tragic or heroic nuance.
Compound of 悲壮 (tragic heroism) + 感 (feeling, sense).