A "crazy idea" refers to a thought or suggestion that may seem unusual, unexpected, or impractical. It often implies that the idea is far-fetched or unconventional compared to more traditional or commonly accepted notions. Full definition
As with a lot of things involving pregnancy and babies, there are a lot of crazy ideas about breastfeeding. (pregnancymagazine.com)
CES is one of our favorite times of the year, with crazy ideas sitting right next to amazing ones. (digitaltrends.com)
Similarly, setting up a «shell» corporation is a pretty crazy idea for something like this, and won't likely result in any significant tax savings. (canadiancapitalist.com)