this dreamlike world; this transient life
Archaic Buddhist-influenced expression for the ephemeral, dreamlike nature of worldly existence. Used in classical literature and poetry.
「夢の世」は、このはかない人生を夢にたとえた古い言い回しです。
"Yume no yo" is an old expression that compares this fleeting life to a dream.
Compound of 夢 (yume, 'dream') + の (no, possessive particle) + 世 (yo, 'world'). The exact historical origin is uncertain, but it reflects a classical Buddhist view of reality as illusory.