foible

Etymology

1640–50, from Early Modern Middle French foible (“feeble”) (contemporary French faible). Doublet of feeble.

noun

1. (chiefly in the plural) A quirk, idiosyncrasy, or mannerism; an unusual habit that is slightly strange or silly.
   Try to look past his foibles and see the friendly fellow underneath.
   Final fillip in the Vice-President's study has been a boning up on Premier Khrushchev's favorite foible, proverbs. The bibulous Russian leader likes to throw out homely homilies in his speeches and conversations[…] July 24, 1959, “An Ounce of Prevention”, in Meriden Record, page 6
2. A weakness or failing of character.
   Jesus is reverenced as the one man who has lived unspotted by the world, free from human foibles, able to redeem mankind by his example. 1932, William Floyd, The Mistakes of Jesus
3. (fencing) Part of a sword between the middle and the point, weaker than the forte.

adj

1. (obsolete) Weak; feeble.
   The good Fencing-maſters, in France eſpecially, when they preſent a Foyle or Fleuret to their Scholars, tell him it hath two Parts, one of which he calleth the Fort or ſtrong, and the other the Foyble or weak […] a. 1648, Edward Herbert, 1st Baron Herbert of Cherbury, The Life of Edward Lord Herbert of Cherbury, page 46