The weaker section of a sword blade, from the middle to the tip.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "foible" in a sentence
"But I think my only foible is really spending so long in this other world."
"When I bring up the latest Palin foible, my GOP co-workers ask me if I am afraid of Palin."
"Upon these considerations, he met with a most engaging reception from the entertainer, who was a well-bred man, of some learning, generosity, and taste; but his foible was the desire of being thought the inimitable pattern of all three."