Quick Definition
ἄνθραξ, ακος, ὁ n.m. a coal
Strong's Definition
of uncertain derivation; a live coal
KJV Usage: coal of fire
UBS Dictionary of the Greek New Testament
noun, m. | -ακος | ἀνθρακιά
3.67 · Plants · Wood and Wood Products
charcoal ἄνθραξ occurs in the NT only in ROM 12:20 in the adage ἄνθρακας πυρὸς σωρεύσεις ἐπὶ τὴν κεφαλὴν αὐτοῦ ‘heap coals of fire on his head.’ This idiomatic expression probably refers to making someone blush with shame and remorse (see 25.199).
In rendering ἄνθρακας πυρός it is not necessary to use a word which specifically refers to ‘flaming charcoal.’ What is important is that the embers be understood as ‘fiery embers’ or ‘hot ashes’ or ‘burning ashes.’
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
ἄνθραξ, -axos, 6, coal, (also, fr. Thuc. and Arstph. down, a live coal), ἄνθρ. πυρός a coal of fire i. e. a burning or live coal; Ro. xii. 20 ἄνθρ. πυρὸς σωρεύειν ἐπὶ τὴν κεφαλήν > ta ἀνθρωπάρεσκος
Mounce Concise Greek Dictionary
ἄνθραξ anthrax 1x
a coal, burning coal, Rom. 12:20*
Abbott-Smith Greek Lexicon
ἄνθραξ, -ακος, ὁ,
[in LXX chiefly for גַּחֶלֶת;]
coal, charcoal: . ἄ. πυρός, a burning coal, Ro 12:20.†
Moulton & Milligan — Vocabulary of the Greek NT
ἄνθραξ. P Petr III. 107(@)*, P Lond 1159 (a.p. 145-7) (=III. p. 113) ἐπὶ ξυλ καὶ ἀνθράκων kal dave καὶ λαμπάδ, ii/iil The word also occurs ter in Michel 594 (B.C. 279), a long inscription from Delos containing the receipts and expenses of the ἱεροποιοί. It is MGr ἄνθρακας.
Liddell-Scott-Jones — Greek-English Lexicon
ἄνθραξ (anthrax) — charcoal. ἄνθραξ, ᾰκος, ὁ, charcoal, [Refs 4th c.BC+]: mostly in plural ἄνθρακες[Refs 5th c.BC+]; their vapour produced stupor, [Refs 4th c.BC+] of a glutton, [Refs 3rd c.BC+]
2. coal, οἷς καὶ οἱ χαλκεῖς χρῶνται[Refs 4th c.BC+]; ἐπὶ ἀνθράκων μαλακῶν on a slow fire, [Refs 1st c.AD+]
II. a precious stone of dark-red colour, including the carbuncle, ruby, and garnet [LXX+4th c.BC+]
II.2. hence, carbuncle, malignant pustule (accusative to some, small-pox), [Refs 5th c.BC+]
III. ={ἰσάτις}, woad, [Refs]