and CREATION (5 letters) The term INVENTION NECESSITY is composed of two words: IDEA (4 letters) and CREATION (5 letters). An invention is an IDEA or CREATION that is novel and provides a solution to a problem. Necessity is the need for something, so an invention necessity is the need for an IDEA or CREATION to solve a problem. Inventions are often the result of creative thinking and problem solving, and can be used to improve existing products or create entirely new ones.