Are you aware of any other definition that has legal standing?
A fundamental right may or may not be a natural, God-given right (and Publius Huldah argues it is not a natural right), but the key is in the allowing for restrictions on that right, which this amendment does.
Alabama Constitution Article 1 - Section 26 - Right to Bear Arms "That every citizen has a right to bear arms in defense of himself and the state." Art. I, § 26 (enacted 1819, Art. I, § 23, with "defence" in place of "defense," spelling changed 1901).
Article 1 - Section 36 - Construction of Declaration of Rights That this enumeration of certain rights shall not impair or deny others retained by the people; and, to guard against any encroachments on the rights herein retained, we declare that everything in this Declaration of Rights is excepted out of the general powers of government, and shall forever remain inviolate.
I'm not a legal scholar, but it sounds as if the current laws don't really need revision. Just my two cents worth.