The word "conception" refers to the starting point or beginning of an idea, a plan, or the creation of something. It can also describe the process of a woman becoming pregnant. Full definition
Having been involved from the time of conception of the idea, naturally, I was the one he called. (sciencemag.org)
Content editors deal with the writing process starting from conception of the idea to preparing the final document for digital or print media. (resumesamplesdownload.in)
She says authors should start thinking about publicity at conception of the idea, and while they're writing the book. (janefriedman.com)