Strong's #5: Abba (pronounced ab-bah')

of Chaldee origin (2); father as a vocative:--Abba.

Thayer's Greek Lexicon:

̓͂

Abba

Abba = "father"

1) father, customary title used of God in prayer. Whenever it occurs in the New Testament it has the Greek interpretation joined to it, that is apparently to be explained by the fact that the Chaldee "ABBA" through frequent use in prayer, gradually acquired the nature of a most sacred proper name, to which the Greek speaking Jews added the name from their own tongue.

Part of Speech: noun

Relation: of Aramaic origin H2

Usage:

This word is used 3 times:

 

Mark 14:36: "And he said, Abba, Father, all things are possible unto thee; take away"
Romans 8:15: "of adoption, whereby we cry, Abba, Father."
Galatians 4:6: "your hearts, crying, Abba, Father."