Apparently a primary word; a "son" (sometimes of animals), used very widely of immediate, remote or figuratively, kinship -- child, foal, son.
1. properly,
a. rarely of the young of animals: Matthew 21:5 (Psalm 28:1 b. in a wider sense (like θυγάτηρ, τέκνον), a descendant, one of the posterity of anyone: τίνος, Matthew 1:20; ὁ υἱός Δαυίδ, of the Messiah, Matthew 22:42, 45; Mark 12:35, 37; Luke 20:41, 44; of Jesus the Messiah, Matthew 9:27; Matthew 12:23; Matthew 15:22; Matthew 20:30; Matthew 21:9, 15; Mark 10:47; Luke 18:38f plural υἱοί τίνος, Matthew 23:31; Hebrews 7:5; υἱοί Ἰσραήλ, Israelites (the children of Israel), Matthew 27:9; Acts 9:15; Acts 10:36; 2 Corinthians 3:7, 13; Hebrews 11:21; Revelation 2:14; Revelation 7:4; Revelation 21:12 (see Ἰσραήλ); υἱοί Ἀβραάμ, sons of Abraham, is tropically applied to those who by their faith in Christ are akin to Abraham, Galatians 3:7. 2. tropically and according to the Hebrew mode of speech (Winer's Grammar, 33 (32)), υἱός with the genitive of a person is used of one who depends on another or is his follower: οἱ υἱοί of teachers, equivalent to pupils (see τέκνον, b. β. (cf. Irenaeus haer. 4, 41, 2 qui enim ab aliquo edoctus est, verbo filius docentis dicitur, et ille eius pater)), Matthew 12:27; Luke 11:19; τοῦ πονηροῦ, who in thought and action are prompted by the evil one and obey him, Matthew 13:38; υἱός διαβόλου, Acts 13:10; with the genitive of a thing, one who is connected with or belongs to a thing by any kind of close relationship (Winers Grammar, § 34, 3 N. 2; Buttmann, § 132, 10): υἱοί τοῦ νυμφῶνος (see νυμφών), Matthew 9:15; Mark 2:19; Luke 5:34 (τῆς ἄκρας, the garrison of the citadel, 1 Macc. 4:2; in Ossian 'a son of the hill' i. e. 'a hunter', 'a son of the sea' i. e. 'a sailor'; cf. Jen. Lit. Zeit. for 1836 No. 58, p. 462f); τοῦ αἰῶνος τούτου, those whose character belongs to this age (is 'worldly'), Luke 16:8; Luke 20:34; τῆς ἀπειθείας, i. e. ἀπειθεῖς, Ephesians 2:2; Ephesians 5:6; Colossians 3:6 (here T Tr WH omit; L brackets the clause) (ἀνομίας, Psalm 88:23 STRONGS NT 5207a: υἱός τοῦ ἀνθρώπουυἱός τοῦ ἀνθρώπου, the Sept. for אָדָם בֶּן, Chaldean אֲנָשׁ בַּר, son of man; it is: 1. properly, a periphrasis for 'man' especially common in the poetic books of the O. T., and usually carrying with it a suggestion of weakness and mortality: Numbers 23:19; Job 16:21; Job 25:6; Psalm 8:5; Isaiah 51:12; Sir. 17:30 (25), etc.; often in Ezekiel, where God addresses the prophet by this name, as Ezekiel 2:1, 3; Ezekiel 3:1 (Ezekiel 2:10), etc.; plural הָאָדָם בְּנֵי (because אָדָם lacks the plural), υἱοί τῶν ἀνθρώπων, Genesis 11:5; 1 Samuel 26:19; Psalm 10:4 2. In Daniel 7:13f, cf. 18, 22, 27, the appellation son of man (אֱנָשׁ בַּר) symbolically denotes the fifth kingdom, universal and Messianic; and by this term its humanity is indicated in contrast with the barbarity and ferocity of the four preceding kingdoms (the Babylonian, the Median, the Persian, the Macedonian) typified under the form of beasts (verse 2ff). But in the Book of Enoch (written toward the close of the 2nd century before Christ (but cf. B. D. (especially American edition); Lipsius in Dict. of Chris. Biog. under the word; Dillmann in Herzog (2nd edition, vol. 12, p. 350f); Schodde, Book of Enoch, p. 20ff)) the name 'son of man' is employed to designate the person of the Messiah: 46, 2f; 48, 2; 62, 7, 9, 14; 63, 11; 69, 26f; 70, 1; 71, 17. (The chapters in which the name occurs are the work, if not of the first author of the book (as Ewald and Dillmann think (but see B. D. American edition, p. 740{b}; and Herzog as above, p. 351)), at least of a Jewish writer (cf. Schürer, Neutest. Zeitgesch. § 32 V. 2, p. 626), certainly not (as Hilgenfeld, Volkmar, Keim, and others imagine) of a Christian interpolator.) In the language of the Jews in John 12:34 the titles Χριστός and υἱός τοῦ ἀνθρώπου are used as synonyms. 3. The title ὁ υἱός τοῦ ἀνθρώπου, the Son of Man, is used by Jesus of himself (speaking in the third person) in Matthew 8:20; Matthew 9:6; Matthew 10:23; Matthew 11:19; Matthew 12:8, 32, 40; Matthew 13:37, 41; Matthew 16:13, 27; Matthew 17:9, 12, 22; Matthew 18:11 Rec.; STRONGS NT 5207b: υἱός τοῦ Θεοῦυἱός τοῦ Θεοῦ son of God; 1. in a physical sense, in various applications: originating by direct creation, not begotten by man — as the first man Adam, Luke 3:38; Jesus, begotten of the Holy Ghost without the intervention of a human father, Luke 1:35; in a heathen sense, as uttered by the Roman centurion of Jesus, a 'demigod' or 'hero', Matthew 27:54; Mark 15:39. 2. in a metaphysical sense, in various applications: plural, of men, who although the issue of human parents yet could not come into being without the volition of God, the primary author of all things, Hebrews 2:10, cf. vss. 11, 13; of men as partaking of immortal life after the resurrection, and thus becoming more closely related to God, Luke 20:36; of angels, as beings superior to men, and more closely akin to God, Deuteronomy 32:43; for אֱלֹהִים בְּנֵי in the Sept. of Genesis 6:2, 4; Psalm 28:1 3. in a theocratic sense: of kings and magistrates, as vicegerents of God the supreme ruler, 2 Samuel 7:14; Psalm 2:7; υἱοί ὑψιτου, Psalm 81:6 4. in an ethical sense with very, various reference; those whom God esteems as sons, whom he loves, protects and benefits above others: so of the Jews, Deuteronomy 14:1; Wis. 12:19ff Wis. 18:4; υἱοί καί θυγατέρες τοῦ Θεοῦ, Isaiah 43:6; Wis. 9:7; πρωτότοκος τοῦ Θεοῦ, Exodus 4:22; in the N. T. of Christians, Romans 9:26; Revelation 21:7; those whose character God, as a loving father, shapes by chastisement, Hebrews 12:5-8; those who revere God as their father, the pious worshippers of God, Wis. 2:13 (here παῖς κυρίου),18; those who in character and life resemble God (Sir. 9:10 υἱοί ὑπιστου; (cf. Epictetus dissert. 1, 9, 6)): Matthew 5:9, 45; υἱοί ὑψίστου, Luke 6:35; υἱοί καί θυγατέρες, spoken of Christians, 2 Corinthians 6:18; those who are governed by the Spirit of God, Romans 8:14 (ὅσοι πνεύματι Θεοῦ ἄγονται, οὗτοι υἱοί εἰσί τοῦ Θεοῦ), repose the same calm and joyful trust in God which children do in their parents, Romans 8:14ff; Galatians 3:26; Galatians 4:6f, and hereafter in the blessedness and glory of the life eternal will openly wear this dignity of sons of God, Romans 8:19 (ἀποκάλυψις τόν υἱῶν τοῦ Θεοῦ), cf. 1 John 3:2 (see τέκνον, b. γ (and references)), preeminently of "Jesus, as enjoying the supreme love of God, united to him in affectionate intimacy, privy to his saving counsels, obedient to the Father's will in all his acts": Matthew 11:27; Luke 10:22; John 3:35; John 5:19f. In many passages of the writings of John and of Paul, this ethical sense so blends with the metaphysical and the theocratic, that it is often very difficult to decide which of these elements is predominant in a particular case: John 1:34; John 3:17; John 5:21-23, 25; John 6:40; John 8:35; John 11:4; John 14:13; John 17:1; 1 John 1:3, 7; 1 John 2:22-24; 1 John 3:8, 23; 1 John 4:10, 14; 1 John 5:5, 9-13, 20; 2 John 1:3, 9; Romans 1:3, 9; Romans 5:10; Romans 8:3, 29, 32; 1 Corinthians 1:9; 1 Corinthians 15:28; 2 Corinthians 1:19; Galatians 1:16; Galatians 2:20; Ephesians 4:13; 1 Thessalonians 1:10; ὁ υἱός τῆς ἀγάπης αὐτοῦ (i. e. God's), Colossians 1:13; ὁ Χριστός ὁ υἱός τοῦ Θεοῦ John 20:31; ὁ μονογενής υἱός, John 1:18 (here Tr WH μονογενής Θεός, L marginal reading ὁ μονογονης Θεοῦ (see μονογενής and references)); John 3:18; ὁ υἱός τοῦ Θεοῦ ὁ μονογονης, John 3:16; 1 John 4:9 (see μονογενής). It can hardly be doubted that a reverent regard for the transcendent difference which separates Christ from all those who by his grace are exalted to the dignity of sons of God led John always to call Christians τέκνα τοῦ Θεοῦ, not as Paul does υἱοί and τέκνα τοῦ Θεοῦ indiscriminately; the like reverence moved Luther to translate the plural υἱοί τοῦ Θεοῦ everywhere by Kinder Gottes; (cf., however, τέκνον, b. γ. and references). This appellation is not found in 2 Thessalonians, Philippians, Philemon, the Pastoral Epistles, nor in 1 Peter or in the Epistle of James.