when pigs fly!
- Never!► “James DeLong . . . flew to Dallas to recruit Southwest Airlines, the large successful low-fare carrier. They weren’t successful, but Mr. DeLong was heartened when Southwest Chairman Herb Kelleher didn’t give them the response he had in past meetings: ‘When pigs fly.’ ” (Wall Street Journal, Feb. 6, 1996, p. A1)
American business jargon. 2014.