B1
something which has been designed or created for the first time, or the act of creating or designing something
Dictionary examples:
My uncle's latest invention is a pillow that laughs at your jokes. (0.0)
His invention of a pizza-flavored toothpaste didn't win any fans. (0.0)
Her invention of a hat that makes coffee was a real head-turner. (0.0)
a most amazing invention (21.7)
The world changed rapidly after the invention of the telephone. (33.1)