ˌno-ˈbrainer BrE AmE noun [singular]
a decision that is easy, and that you do not need to think about, used when you want to emphasize that it is really very easy:
Joining the savings plan is a no-brainer. Just do it.
ˌno-ˈbrainer BrE AmE noun [singular]
a decision that is easy, and that you do not need to think about, used when you want to emphasize that it is really very easy:
Joining the savings plan is a no-brainer. Just do it.
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012