KJV Deuteronomy 4:2 Ye shall not add unto the word which I command you, neither shall ye diminish ought from it, that ye may keep the commandments of the LORD your God which I command you.

In the Hebrew, the word behind lord is YHVH. This name, whose pronunciation is not known for certain, is usually written as Yahweh, or Jehovah. Just like all other Hebrew names, the name YHVH has a meaning, and it isn't lord. It means 'he exists.'

If your name is Bob, but I never called you "Bob", but instead called you "man," would you agree that I have "diminished" your name? 6519 times the name Yahweh/Jehovah has been diminished by being replaced with the English word "Lord."

Right here in Deut 4:2, the very command telling us not to add to or diminish from the word of YHVH, we have the KJV translators diminishing his very name and adding a different word in place of it.