knock the wind out of sails
knock the wind out of (one's) sails
1. To diminish one's enthusiasm, excitement, or positive outlook (about something). Sorry, I didn't mean to knock the wind out of your sails or anything. I just don't want you getting your hopes up about this. It really knocked the wind out of his sails to learn that nearly half of his bonus would go to taxes.
2. To diminish one's momentum or motivation to succeed. You can tell that the crowd's deafening applause for the home team is starting to knock the wind out of their opponents' sails. The scandal knocked the wind out of their sails, and they trailed in the polls for the rest of the election.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
knock the wind out of someone's sails
1. Lit. to bring someone to an abrupt halt by a heavy blow to the body, presumably knocking the person's wind out. (Alludes to a ship being slowed by positioning another ship to block off the wind from the first ship's sails.) Fred hit Mike and really knocked the wind out of his sails. Fred ran into the side of the garage and knocked the wind out of his sails.
2. Fig. to humiliate someone. The sharp rebuke from the boss knocked the wind out of his sails. That scolding really knocked the wind out of her sails.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.