Invention, informally (10)
I believe the answer is:
brainchild
(Other definitions for brainchild that I've seen before include "Original idea or work" , "Bright idea" , "One's original idea" , "Invention" , "wheeze" .)
I believe the answer is:
brainchild
(Other definitions for brainchild that I've seen before include "Original idea or work" , "Bright idea" , "One's original idea" , "Invention" , "wheeze" .)