LORD, in upper case letters, appears 6,510 times in the English Old Testament. This is not a translation of some Hebrew word meaning Lord, but of YHWH, the name of God.
This name was first revealed to Moses in the account of the burning bush Exodus chapter 3. God tells Moses that His name is I AM. When this was written out in the Scripture it was written YHWH in Hebrew letters.
The Hebrew alphabet is only 22 letters, all consonants. Apparently this is not as much of a problem in Hebrew as it would be in English or French, due to a lesser number of vowel sounds.
Hundreds of years later vowel points were added to Hebrew, but in the meantime the pronunciation of YHWH was lost as it was thought to be a sin to pronounce the name of God. This came from the desire to avoid violating the commandment which says “Thou shalt not take the name of the LORD thy God in vain.”
Rather than pronounce YHWH the Hebrew people would substitue another word, most often Adonai, which means Lord. Whe vowel points were added to the Hebrew alphabet the voels of Adonai were inserted in YHWH, which gave Yahovah. This is undoubtedly the wrong pronunciation. To be true to the origin of YHWH in the Hebrew word for I AM, the name needs to be pronounced Yahweh (or Yahveh).
I think many readers of the Bible misunderstand the meaning of LORD in the Old Testament. It does not mean that the name of God means Lord, but simpply follows the Jewish practice of substituting Lord for the name of God. Many Jews today will not pronounce God in English and write it as G-D, omitting the vowel.
In French Bibles YHWH is translated as l’Éternel (the Eternal) which nicely captures the meaning of I AM as the name of God. But then in the New Testament French Bibles use Seigneur (Lord) just like English Bibles use Lord. The substitution of Lord for YHWH was so thoroughly entrenched by that time that New Testament writers used kurios, the Greek word for Lord to refer to God.