We need a “definition” of “the right to keep and bear arms” as opposed to just saying it “shall not be infringed” without stating exactly what “it” is.
No we do not. The right to keep (own, possess, and control control) and bear (carry anywhere anytime) shall not be infringed (no law may prevent). Read the Federalist Papers, they explain the Bill of Rights very clearly.
The Federalist Papers is a collection of 85 articles and essays written by Alexander Hamilton, James Madison, and John Jay under the collective pseudonym "Publius" to promote the ratification of the United States Constitution. The collection was commonly known as The Federalist until the name The Federalist Papers emerged in the 20th century.
The right to keep and bear arms shall not be infringed. What more do you need? The words are not obscure. Their meaning is plain.