IPA: /nʊəˈræstθɛnɪk/
KK: /nʊrəsˈθɛnɪk/
Relating to a condition characterized by physical and mental exhaustion, often due to stress or emotional strain.
After months of stress at work, she felt neurasthenic and needed a break to recover.
Comparative: more neurasthenic
Superlative: most neurasthenic
Neurasthenic is formed from "neuro-" (from Greek "neuron", meaning nerve) and "asthenia" (from Greek "astheneia", meaning weakness). The term describes a condition characterized by nerve weakness or fatigue.
Think of 'nerves' ('neuro-') being 'weak' ('asthenia') — that's why neurasthenic refers to someone experiencing nerve weakness or fatigue.