The word Adar is cognate to the Hebrew word "adir", meaning "strength".

Adar is the month of good fortune for the Jewish people.

"Adar" means "exalted", "praised", "power", and "strength". where it says: "the Lord is (Adir) mighty on High".

This opinion states that just as we decrease our joy because we are separated from the Shechina (God's presence) in the month of Av,

so too in Adar we rejoice because the whole month is a time when the Shechina (God's presence) is close to us.

When God commanded Moses to construct the tabernacle, He made the following request: make for Me a small chamber (called Mishkan in Hebrew) so that I may live (dwell in your midst).

1 Corinthians 6:19 says; do you not know that your body is the temple of the Holy Spirit who is in you, whom you have from God, and you are not your own?

It is said that the word "v'edor" ("and I will dwell" in Hebrew) is related to the word "adar" - the very name of this month implies that it is a time when the Shechina (God's presence) dwells among us "v'edor beineichem".

Another opinion states that the word "Adar" means "beauty", as in the beauty of the season contained in Adar, Spring.

Adar II

Hebrew months are alternatively 30 and 29 days long, Their year is a bit shorter (354 days) than the worlds year (365 days). So about every 3 years (7 times in 19 years) an extra 29– day month, Adar II, is added between Adar and Nissan.