brainchild

or brain-child, brain child

[ breyn-chahyld ]
/ ˈbreɪnˌtʃaɪld /

noun, plural brain·chil·dren.

a product of one's creative work or thought.

Origin of brainchild

First recorded in 1880–85; brain + child

British Dictionary definitions for brain child

brainchild
/ (ˈbreɪnˌtʃaɪld) /

noun plural -children

informal an idea or plan produced by creative thought; invention