debility

noun

1. (countable, uncountable)A state of physical or mental weakness.

   “As I was in a state of extreme debility, I resolved to sail directly towards the town, as a place where I could most easily procure nourishment. […] I was ready to sink from fatigue and hunger, but being surrounded by a crowd, I thought it politic to rouse all my strength, that no physical debility might be construed into apprehension or conscious guilt.”

   “I was struck besides with the shocking expression of his face, with his remarkable combination of great muscular activity and great apparent debility of constitution”

   “At the mention of money Mrs Dibble was overcome with great debility, and wheezed, "I don't feel up to talking about money, matters just now, dearie. I think I better have a bit of a doze."”