🔼The name Adonai in the Bible
Adonai by itself is not really a proper name but rather a title or appellative. As we will see below, it quite literally means 'mister' or my lord, master or owner, and is not unlike the word baal, which means the same. Yet adon(ai) occurs frequently as element in compound names: Adoni-bezek, Adonijah, Adonikam, Adoniram and Adoni-zedek.
Adonai is also the source of the fabricated name Jehovah. When the Masoretes wanted to preserve the pronunciation of the words used in the Bible they ran into a problem when YHWH, the proper name of the Lord that was forbidden to be pronounced, occurred. To circumvent the problem, the Masoretes inserted the vowel symbols that go with adonai, indicating that whenever the reader saw YHWH, he had to say adonai.
When later readers saw the name YHWH combined with the symbols for adonai, they erroneously concluded that YHWH was to be pronounced as Jehovah.
🔼Etymology of the name Adonai
The word adonai comes from the unused root אדן ('dn), of which the meaning is disputed, says BDB Theological Dictionary, and lists the following proposals: Some say it's comparable to the Assyrian word adannu, meaning firm or strong, and the associated adverb adannis means strongly or exceedingly. Others say it may have to do with a Persian word meaning firm or fasten, and thus it means to determine, hence command, hence rule. Others still propose relations to an Arabic verb that means to be obedient or cause obedience, hence govern and rule. This verb is thought to have to do with the Hebrew word דין (din), meaning to judge, and thus with the name דן (Dan), and also makes the best candidate morphologically spoken:
The name Adonai literally means My Fundament and by implication My Lord, but can be used autonomously to refer to a person upon whom society stands: Milord or simply Sir or Mister.
It should be noted that the Hebrew authors saw themselves as the autonomous agents of the Creator's doings, much rather than His blindly obedient slaves or even lifeless pawns He moves at will. The Hebrews called the Creator 'mister Yahweh', and addressed them the way any of us would address our CEO in a business meeting.
People who slavishly call their CEO 'Lord LORD' or something along those lofty lines are probably slacking or up to something.