a revolutionary new idea or concept, having mostly a positive effect to society.
The assembly line was the brainchild of Henry Ford, ushering in mass production of automobiles and significantly reducing their price for a while.
by Polo July 16, 2006
Brainchild is a word to describe an incredibly smart kid with an exceptionally large head. A brainchild usually gets bullied for having such a big head, but he knows how not to take offence.
Look at that dumb Brainchild, he has such a big head
by Big dick bois January 10, 2022
a sarcastic term used to describe someone who is being amazingly stupid
Cos now my back's really starting to ache
Yeah my eyes are getting heavy and I can't stay awake
The DJ on the radio's really starting to vex me
And if nobhead gets any closer then he's gonna scratch me
Cos I can feel the pressure rising, like that film, falling down
The light's are green BRAINCHILD, what you waiting for?
Cruising around in your X5 Jeep with your 14" rims
And your cream leather seats
With your starbucks in one hand and your 6310 in the other
Whats your problem, you stupid mother?

(Trip to the golden Arches by Bromheads jacket)
by Starry June 14, 2006
A child with an unnaturally large brain that protudes from the child's head reaching up to 3 metres in all directions. A brainchild's brain has the capability of fatally crushing unsuspecting bystanders should they stray too close to the spectacle.
"That Emily is a brainchild"
"The brainchild's brain broke every bone in Terrance's body."
by Rossetta3123 September 10, 2006
To misuse or attack someone's well thought out concept to a disgusting extent.
I had a solution to the fund-raising problem, but Herb messed up my idea so much that we're now being sued. He sure knows how to molest a brainchild.
by AbnormalBoy January 6, 2007