brainchild
n.an idea or a project that someone has created or thought of. It is often used to describe something that took a lot of time and effort to make.
n.an idea, invention, or project that has been conceived or created by a specific person. Often carries a slightly informal or affectionate tone when referring to a complex or ambitious undertaking.
“The new app is the brainchild of a small team of students.”
“The community garden was the brainchild of a local teacher who wanted to bring people together.”
“While the initial concept was a simple sketch, the final skyscraper proved to be the brainchild of an architect whose vision had been shaped by years of studying urban density.”
“It was the brainchild of Abby Tomlinson, a 17-year-old sixth-form student, who came to the defence of the man she called "Milibae".”
“What are your suggestions?” In an interview with Soo Today , Broadbent said the funny post was the brainchild of “me and our team.” “These are difficult times,” said Broadbent.”
From brain + child.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.