sense of emptiness; feeling of meaninglessness
A psychological or philosophical feeling that life or a situation lacks meaning, purpose, or substance. Often used in literary, psychological, or everyday contexts to describe a hollow or empty emotional state.
Caught up in work every day, I sometimes get hit by a sense of emptiness.
Even after succeeding, he couldn't shake off the feeling of meaninglessness.
無力感 is a feeling of powerlessness or helplessness, focusing on inability to act, whereas 虚無感 is about the absence of meaning or substance.
Compound of 虚無 (kyomu, 'nothingness, nihility') and 感 (kan, 'feeling, sensation'). The exact historical derivation is uncertain, but the word follows a common pattern for expressing emotional or sensory states.