IPA: /ˌɛn.əˈveɪ.ʃən/
KK: /ɛnərˈveɪʃən/
The state of feeling weak or tired, often due to a lack of energy or strength.
After a long day at work, I felt a sense of enervation that made it hard to focus on anything else.
Enervation is formed from "e-" (meaning out of or from) and "nervus" (meaning nerve or sinew). The word describes the state of being weakened or drained of energy, as if the strength has been taken out of the nerves.
Think of 'nerves' being 'drained' or 'taken out' ('e-') — that's why enervation means a loss of strength or energy.