noun
feeling of despondency; sense of emptiness; dejection
Describes a hollow, drained emotional state, often after disappointment or exhaustion. More psychological than physical.
試験に落ちて、虚脱感に襲われた。
After failing the exam, I was overcome by a feeling of despondency.
目標を失った彼は、しばらく虚脱感から抜け出せなかった
Having lost his goal, he couldn't shake off the sense of emptiness for a while.
脱力感 emphasizes physical weakness or loss of strength, whereas 虚脱感 is more about emotional emptiness and despondency.
Compound of 虚脱 (kyodatsu, 'prostration; lethargy') and 感 (kan, 'feeling; sensation'). The exact historical derivation is uncertain, but the word follows a common pattern for expressing subjective states.