The phrase "common notion" refers to an idea or belief that is widely accepted or understood by most people. It is something that people generally agree on and consider to be true. Full definition
That very common notion of the time implied that pastoral calls were the knowing, and if the people came to church to hear the sermon that was the feeding. (religion-online.org)
Therefore, despite common notions to the contrary, the net lease market is open to investors with smaller amounts of equity. (nreionline.com)
Nevertheless, her reaction reflects an all - too - common notion in the media: tragedy must be followed immediately by a call to action. (firstthings.com)