frailty

The condition quality of being frail, physically, mentally, or morally; weakness of resolution; liability to be deceived.

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 ;

For all their frailty at the back, Arsenal possessed genuine menace in attack and they carved through Chelsea with ease to restore parity nine minutes before half-time. Aaron Ramsey's pass was perfection and Gervinho took the unselfish option to set up Van Persie for a tap-in.

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