one's last journey; journey to the other world; death
A poetic or euphemistic expression for death, often used in literary or solemn contexts. Literally 'the journey of departing for death'.
He quietly set out on his last journey.
Thinking about the journey to the other world makes my heart heavy.
Means 'departure' or 'setting out on a journey' in a general sense, not inherently linked to death. 死出の旅 is specifically the final journey of death.
Compound of 死出 (shide, 'departing from life; death') + の (no, possessive particle) + 旅 (tabi, 'journey'). The word 死出 itself is an old compound of 死 (shi, 'death') and 出 (de, 'going out'). The phrase is rooted in traditional Japanese views of death as a journey to the afterlife.