Lacking strength of character or purpose.(adjective)
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 "weak-kneed" in a sentence
"Rebello also expressed his desire to see a more nationalist party defeat Jean Charest's Liberals, whom he described as weak-kneed when dealing with Ottawa."
"As my idea to enroll at LeCoq became a decision that spring, I hadn't anticipated that, come late summer, with the plane ticket purchased and an eleven-month lease signed, an abrupt shift in the exchange rate that ran in favor of the Euro would pull the rug out from under my savings, and leave it weak-kneed and wobbly."
"* If victorious GOP candidates think the Tea Party is going to let them get away with going weak-kneed and being all responsible and moderate next year, they've got another thing coming."