Quick Definition
ἀδελφότης, τητος, ἡ n.f. brotherhood
Strong's Definition
from 80; brotherhood (properly, the feeling of brotherliness), i.e. the (Christian) fraternity
KJV Usage: brethren, brotherhood
UBS Dictionary of the Greek New Testament
noun, f. | -ητος | ἀδελφός
11.22 · Groups and Classes of Persons and Members of Such Groups and Classes · Socio-Religious
brotherhood, fellow believers an association of persons having a strong sense of unity It is often quite impossible to speak of fellow Christians as ‘the brothers and sisters,’ since a number of receptor languages do not permit this type of extension of meaning from an underlying base meaning ‘brother’ or ‘sister.’ Therefore, it may be necessary to speak of ‘fellow believers’ or ‘those who believe together with others’ or ‘those who likewise believe.’ See also discussion at 11.23.
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
ἀδελφότης, -ητος, ἡ, brotherhood; the abstract for the concrete, a band of brothers i. e. of Christians, Christian brethren: 1 Pet. ii. 17; v. 9. (1 Mace. xii. 10, 17, the connection of allied nations; 4 Mace. ix. 23; x. 3, the connection of brothers; Dio Chrys. ii. 137 [ed. Reiske]; often in eccl. writ.)
Mounce Concise Greek Dictionary
ἀδελφότης adelphotēs 2x
brotherhood, the body of the Christian brotherhood, 1 Pet. 2:17; 5:9*
Abbott-Smith Greek Lexicon
**† ἀδελφότης, -ητος, ἡ
(< ἀδελφός), [in LXX: I Mac 12:10, 17, IV Mac5*;]
abstract, brotherhood, brotherly affection (LXX).
Concrete, the brotherhood, the Christian community: I Pe 2:17 5:9 (MM, VGT, s.v.).†
Moulton & Milligan — Vocabulary of the Greek NT
ἀδελφότης addressing her Azsband, not brother : see Kenyon’s note ad /. where Letronne’s statement that the Ptolemies called their wives ἀδελφαί even where they were not actually so is quoted. Witkowski £//.2 p. 61 maintains this against Wilcken, quoting Wilamowitz (Gr. Zeseduch I. p. 397), and noting that Isias says ἡ μήτηρ σου, showing that Isias and Hephaestion were not children of the same mother. Cf. also P Par 45 and 48 (ii/B.c.) where men address with τῷ ἀδελφῷ χαίρειν men who are no relation to them. For the use of ἀδελφοί to denote members of the same religious community cf. P Tor I. 1-20 (ii/B.c.) where the members of a society which had to perform a part of the ceremony of embalming bodies are described as ἀδελφῶν τῶν τὰς λειτουργίας ἐν ταῖς vekpiats παρεχομένων, and in P Par q2iete. (jj/B.c.) the same designation is applied to the “fellows” of a religious corporation established in the Serapeum of Memphis. In P Tebt I. 12 (8.6. 118) Crénert assumes that one town clerk addresses another as ἀδελφός : Grenfell and Hunt take it literally—see their introduction. Cronert quotes also Sy// 607 (tii/iv A.D.), where it is used between two δεκάπρωτοι, and OG/S 2572 (B.c. 109), where one king so addresses another. In this last case the kings were the sons of sisters, but Dittenberger warns us against taking ἀδελφός as used loosely for ἀνεψιός. He refers to OGTS 1383 (ii/B.c.), where Ptolemy Euergetes II. addresses as ‘‘brother” one Lochus, who in other inscriptions is ovyyevqs—‘‘ our trusty and well-beloved cousin,” as an English king would have put it. ᾿Αδελφέ as a term of address may be illustrated by P Flor 11. 228 (iii/A.D.), where Palas thrice calls Heroninus ἀδελφέ : in four other letters to him, from about the same time, he only calls him φίλτατος. So P Tebt 11. 314! (ii/A.D.) ἔρρωσό por ἄδελφε, in a letter addressed at the beginning τῷ] τιμιωτάτῳ. (The voc. survives in Pontic MGr &§e\de—elsewhere aSeppé—says Thumb.) A clear case is Βα IV. 1209? (B.c. 23), where Tryphon addresses τῶι ἀδελφῶι, and goes on to write of his correspondent’s late brother as his own former friend: τοῦ εὐκλήρου ἀδελφοῦ cov ἡμῶν δὲ φίλου γενομένου ΠΠετεχῶντος. ᾿Αδελφός as a title of address is discussed in Rhezn. Mus. N.F. ἵν. p- 170. From the Christian papyri we may note P Grenf 11. 73? (late iii/a.D.) (= Selections p. 117) ᾿Απόλλωνι πρεσβυτέρῳ ἀγαπητῷ ἀδελφῷ ἐν K(vupt)w χαίρειν, P. Lond 41711: (c. A.D. 346) ( ΞΞ 11. p. 299, Selections p. 123) τῷ δεσπότῃ μου καὶ ἀγαπητῷ ἀδελφῷ ᾿Αβιννέῳ πραι(ποσίτῳ), and P Jand 11° (iii/iv A.D.) τῷ κυρίῳ μον ἀδελφῷ Πέτρῳ (cf. Wilcken, Archiv vi. p. 295). For the Christian use of the word see Harnack A/isston and Expansion of Christianity" 1. Ῥ. 405 ff. On ἀδελφός ““ improperly” used in the LXX, see anote by Hort 7he Zpestle of St. James, p. 102f.
Liddell-Scott-Jones — Greek-English Lexicon
ἀδελφότης (adelphotēs) — brotherhood. ἀδελφότης, ητος, ἡ, brotherhood, [LXX+1st c.AD+]: metaphorically, of men and animals, [Refs 4th c.AD+]
II. the brotherhood, [NT]
III. as form of address, ἡ σὴ ἀ.[Refs]