loyal spirit; the loyal dead
Refers to the spirit of loyalty, especially of soldiers who died for their country. Often used in memorial contexts such as 忠魂碑 (monument to the war dead). The sense 'the loyal dead' is a metonymic extension.
We offered flowers in front of the monument to the loyal dead.
彼の忠魂は今も語り継がれている。
His loyal spirit is still talked about today.
monument to the war dead; cenotaph for fallen soldiers
Compound of 忠 (loyalty) and 魂 (spirit, soul). The exact historical derivation is uncertain, but the word is conventionally associated with the spirits of loyal soldiers.