Noun

1. The condition quality of being frail, physically, mentally, or morally; frailness; infirmity; weakness of resolution; liability to be deceived or seduced.
   • 1748. David Hume. Enquiries concerning the human understanding and concerning the principles of moral. London: Oxford University Press, 1973. § 36, n. 1.

     the limitations and restraints of civil government, and a legal constitution, may be defended, either from reason, which reflecting on the great frailty and corruption of human nature, teaches, that no man can safely be trusted with unlimited authority ;

2. A fault proceeding from weakness; foible; sin of infirmity.