To weaken physically (a person or animal); now only of agencies that impair nervous ‘tone’, as luxury, indolence, hot or malarious climates. To weaken mentally or morally; to destroy the capacity of (a person, a community, etc.) for vigorous effort of intellect or will. Said esp. of the effects of luxury or sloth. Also, to destroy or impair the vigour of (sentiments, expressions, etc.).