Where does the name Adonai come from?

Lord of all the Earth אֲדֹון כָּל־הָאָרֶץ adon kol-ha’arets

“Behold, the ark of the covenant of the Lord of all the earth is crossing over ahead of you into the Jordan." Josea 3:11 NASB 

הִנֵּה אֲרֹון הַבְּרִית אֲדֹון כָּל־הָאָרֶץ עֹבֵר לִפְנֵיכֶם בַּיַּרְדֵּֽן׃ 

Look at the “Lord of all the Earth” אֲדֹון כָּל־הָאָרֶץ. This form may more accurately translated at Master of All Earth. The term used is Adon Kol-ha’arets, in modern terms we might use the term Land Lord or King of the World. Both are appropriate based on usage.

Here are some more usages:

"It shall come about when the soles of the feet of the priests who carry the ark of the LORD, the Lord of all the earth, rest in the waters of the Jordan, the waters of the Jordan will be cut off, and the waters which are flowing down from above will stand in one heap." Jos 3:13 NASB

The mountains melted like wax at the presence of the LORD,
At the presence of the Lord of the whole earth. Psalm 97:5 NASB

Then he said, “These are the two anointed ones who are standing by the Lord of the whole earth.” Zechariah 4:14

The angel replied to me, “These are the four spirits of heaven, going forth after standing before the Lord of all the earth Zechariah 6:5

Our Lord / Our Master אָדוֹן 'adown

But one of the young men told Abigail, Nabal’s wife, saying, “Behold, David sent messengers from the wilderness to greet our master, and he scorned them. 1 Samual 25:14

“Now therefore, know and consider what you should do, for evil is plotted against our master and against all his household; and he is such a worthless man that no one can speak to him.” 1 Samuel 25:17

But Jonathan replied to Adonijah, “No! Our lord King David has made Solomon king. 1Kings 1:43

“Moreover, the king’s servants came to bless our lord King David, saying, ‘May your God make the name of Solomon better than your name and his throne greater than your throne!’ And the king bowed himself on the bed. 1Kings 1:47

“Let our lord now command your servants who are before you. Let them seek a man who is a skillful player on the harp; and it shall come about when the evil spirit from God is on you, that he shall play the harp with his hand, and you will be well.” 1Sa 16:16

The Lord God הָֽאָדֹן יְהוָה ‘adown YHVH

“Three times a year all your males shall appear before the Lord GOD. Exodus 23:17; Exodus 34:23 says the same, but adds, the God of Israel.

My Lord אֲדֹנָי ‘adonay, ’adonai

A Psalm of David.
The LORD (YHVH) says to my Lord (‘Adonay):
“Sit at My right hand
Until I make Your enemies a footstool for Your feet.” _{Psalms 110 NASB}

The Lord of Lords ַאֲדֹנֵי הָאֲדֹנִים Adonei ha’adonim

“For the LORD your God is the God of gods and the Lord of lords, the great, the mighty, and the awesome God who does not show partiality nor take a bribe. _{Deuteronomy 10:17}

Summary

This is not exhaustive. I put this together because there is foolishness that says that every insertion of Adonai is a replacement for YHVH. It isn’t. The second foolishness is that Adonai is a different god. Again, it isn’t.

The best way to see what Adonai means is that of the words my Lord, like my Landlord, or Lord of the Lands, the Lord over the earth. We even saw that the word Lord referred to men as well as God.

Since we have the same of God, why not use it. Why not use his name regularly?

"You shall not take the name of the Lord your God in vain, for the Lord will not hold him guiltless who takes His name in vain." Exodus 20:7 

The word vain, is the Hebrew word shave’ שָׁוְא that is to make empty, to have no value, so make common.

Those of use who know the Torah, whether Christian or Jew, we do make YHVH, Jehova, Yahovah, common.