Ἀββᾶ
From LSJ
Σοφῷ παρ' ἀνδρὶ (Σοφοῦ παρ' ἀνδρὸς) πρῶτος εὑρέθη λόγος → Apud sapientem inventa est ratio primitus → Bei einem weisen Mann fand man zuerst Vernunft
English (Strong)
of Chaldee origin (אַב); father as a vocative: Abba.
English (Thayer)
(WH (βά), Hebrew אָב father, in the Chaldean emphatic state, אַבָּא i. e. ὁ πατήρ, a customary title of God in prayer. Whenever it occurs in the N. T. (אַבָּא, through frequent use in prayer, gradually acquired the nature of a most sacred proper name, to which the Greek-speaking Jews added the appellative from their own tongue.
Greek Monotonic
Ἀββᾶ: Εβρ. λέξη, πατέρας, σε Καινή Διαθήκη