Usually the spelling has little to do with this answer. Adon roughly translated from the Hebrew refers to the first man. The symbolic reference to God or is accepted. Adonai is a purposely misspelled or hmm lets say that the only reason people read that word in the first place is because the Hebrews have always been rather paranoid about pronouncing the Lord's name as he gave it to them and the little they are willing to recall in scripture are the characters that form the word Adonai but they place the wrong vowel pointings on the spelling so that Adonai is what you read when that isn't what was meant. If you are looking for a similarity and don't want to be laughed out of every linguists parlor you ever air the idea in you might actually look at the connection between the he who bares the symbol of pharaoh as being the rough equivalent to calling themselves God on earth. Sense Abraham gave them that symbology you might say that Pharaoh kept in remembrance, so long as there was a pharoh who remembered why he carried the Ank* in the first place that he was in a way stepping in for Adonai in his responsibility to Egypt but he answered to Amun (or Amon, or the word Christens use to end their prayers Amen which are all the same) or God in heaven and called himself Ra or God on earth.