Quick Definition
βραχίων, ονος, ὁ n.m. the arm, strength
Strong's Definition
properly, comparative of 1024, but apparently in the sense of brasso (to wield); the arm, i.e. (figuratively) strength
KJV Usage: arm
UBS Dictionary of the Greek New Testament
noun, m. | -ονος | βραχύς
76.3 · Power, Force
power (a figurative extension of meaning of βραχίων ‘arm,’ not occurring in the NT) power as an expression of the activity of a person or supernatural being In some languages there is no abstract term for ‘power.’ The equivalent of doing something by the power of someone is ‘someone makes it possible to do’ or, in a figurative sense, ‘someone gives strength to do.’
76.5 · Power, Force
Collocation: βραχίων ὑψηλός
great power, exalted power, marvelous power (an idiom, literally: exalted arm, or: lifted up arm) great power, with the implication of an exalted quality
1 It is possible that χείρ[c], βραχίων[a], and δάκτυλος[b] in the figurative sense of power of an individual differ somewhat in meaning one from the other, but it is impossible to determine this on the basis of existing contexts.
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
βραχίων, -ovos, 6, [fr. Hom. down], the arm: the βραχίων of God is spoken of Hebraistically for the might, the power of God, Lk. i. 51 (cf. Deut. iv. 34; v. 15 ; xxvi. 8) ; Jn. xii. 38 (Is. lili. 1); Acts xiii. 17.
Mounce Concise Greek Dictionary
βραχίων brachiōn 3x
the arm; the arm as a symbol of power, Lk. 1:51; Jn. 12:38; Acts 13:17*
Abbott-Smith Greek Lexicon
βραχίων, -ὀνος, ὁ,
[in LXX, β. Κυρίου, freq. for זְרוֹעַ יהוָֹה ;]
the arm; as in OT, β. Κυρίου, metaph., for the Divine power: Lk 1:51, Jo 12:38 (LXX), Ac 13:17.†
Moulton & Milligan — Vocabulary of the Greek NT
βραχίων. P Oxy III. 490!* (a will—a.p. 124) οὐλὴ βραχείονι δεξιῷ : similarly P Amh II. 1128 (a.p. 128); P Ryl IL 1798 A.D. 127), ete. In Syl/ 615%? (iii/ii Parr IL. ( βρέχω ταύρου δίδοται γλῶσσα καὶ βραχίων, it means a ‘ shoulder” of meat, and so of a ram in 1.8
Liddell-Scott-Jones — Greek-English Lexicon
βραχίων (brachiōn) — arm. βρᾰχίων [Ionic dialect ῐ, Attic dialect ῑ], βράχιστος, comparative and superlative of βραχύς.