Adonai is a term from Hebrew that means "my Lord". This was the name of God used in the Old Testament instead of the divine name of Yahweh (Yahweh), since this one, out of respect, was not to be pronounced.
Adonai reflects the superiority of God, replacing the Tetragrammaton YHWH, or Yahweh. Thus, whenever the tetragram appeared in a biblical text, it was read as "Adonai". Often the tetragram is replaced by the Hebrew word HaShem, which means "The Name".
According to Jewish tradition, the word Adonai, given that it refers to God, also does not it should be used without consideration, nor should it be used in inappropriate places, such as installations. Sanitary.
The word Adonai is often used in expressions that refer to characteristics of God. For example: Shalom Adonai is an expression meaning "the peace of the Lord". It is a greeting that mentions peace, as if to say "the peace of God be with you". The answer to this greeting should be "Adonai Shalom".
The expression "Adonai Kadesh" is related to the Holiness of God, and means "The Lord is Holy".
Many Christian praise and worship songs use the word adonai as a form of reverence and respect for God. One example is the song "Adonai, Aba Pai", by singer Aline Barros.
See also the Meaning of Yeshua.