What you are doing is going outside of Scripture for your understanding. My point is you don’t have to do that with the KJV.
Nothing that E-G said hinted at "going outside of Scripture for your understanding". He said he went to
another translation, which is not "outside of Scripture" (regardless of your opinion on the matter).
I am certain that you did not come to Scripture as a blank slate, and learn the meaning of every word in the KJV by searching out its first usage. Nor do I believe that you have
only looked in the KJV for meanings of words you
initially encountered
in the KJV (it's possible, but unlikely). Those are valid methods of study, but not exclusive. Dictionaries exist, among other things, for the purpose of explaining the meaning and usage of unfamiliar words. There is no shame to using them. What is unfortunate, however, is the absence of a 16th-century-English dictionary to explain the meanings of words
as they were used then. Strong's is a poor substitute for that, and few people have the time to hunt down each instance of a word on their own.
You are free to believe that "the KJV is its own dictionary", but using that as a justification for your KJV-only position it is akin to tying a bandanna over your eyes, sticking your fingers in your ears, and yelling at others that they are blind and deaf.