Lexical Definition

‎συνήθεια‎ synḗtheia (soon-ay'-thi-ah) custom ^G:N-F
from a compound of ‎σύν‎ and ‎ἦθος‎

custom.

• mutual habituation, i.e. usage

Abbott-Smith

** συνήθεια, -ας, ἡ (< ἦθος), [in LXX: IV Mac 2:12 6:13 13:22, 27 * ;]
1. intimacy.
2. habit, custom: Jo 18:39, I Co 11:16; c. gen. obj. (cf. Æschin., 23, 37, and v. MM, xxiv), habitual use, force of habit with respect to, I Co 8:7.†

Abbott-Smith References

Liddell-Scott-Jones

συνήθεια, ἡ,

habitual intercourse, acquaintance, intimacy, αἱ πρὸς ἀλλήλους σ. [Refs 5th c.BC+]; ἡ πολιτικὴ σ. [Refs 5th c.BC+]; καὶ αὐτῷ δέ μοί εἰσι σ. [Refs 3rd c.BC+]; ὢν ἡμῖν ἐν συνηθείᾳ [Refs 3rd c.BC+]

__b sexual intercourse, [Refs 5th c.BC+]
__2 of animals, herding together, [Refs 4th c.BC+]; νέμεσθαι κατὰ συνηθείας in herds,[Refs 2nd c.AD+]; so of soldiers, κατὰ συνηθείας in messes, [Refs 2nd c.BC+]
__II habit, custom, [Refs 5th c.BC+]; plural, φαῦλαι σ. bad habits, [συνήθειαν τοῦ προτέρου βίου 5th-6th c.BC: Plato Philosophus “Respublica” 620a ">Refs 5th c.BC+]; ἐν τοῖς ἤθεσι τοῖς τῆς ἑαυτοῦ συνηθείας in his own accustomed haunts, [Refs]; ἡ σ. τοῦ ἔργου habituation to it, [συνήθειαν τῶν ἀδικημάτων 4th c.BC: Demosthenes Orator 19.3, compare 60.27; πολλῆς.. σ. ἡ ῥητορική 4th-3rd c.BC: Epicurus Philosophus “Fragmenta” 46 ">Refs 5th c.BC+]; τῇ σ. τοῦ εἰδώλου by being used to it, [NT]; practice, [συνήθειαν [prev. author] “Sph.” 248b ">Refs 5th c.BC+]; διὰ τὴν σ. [Refs 4th c.BC+]; κατὰ σ. [συνήθειαν [prev. author] “Lg.” 655e; ἠναγκάσμεθα ὑπὸ συνηθείας [prev. author] “Tht.” 157b ">Refs 5th c.BC+]; σ. ἔχειν τῇ πολιτείᾳ to be used to it, practised in it, [Refs 2nd c.BC+]
__II.2 the customary usage of language, ἐκ σ. ῥημάτων καὶ ὀνομάτων [Refs 5th c.BC+]; εἰς συνήθειαν ἐποίησε τοῦ λόγου τούτου τὴν πόλιν καταστῆναι brought the city to habitual use of this phrase, [Refs 4th c.BC+]; ἡ σ. τῶν Ἑλλήνων, αἱ κατὰ τὰς διαλέκτους σ., [Refs 5th c.BC+]; ἐν τῇ τεχνικῇ καὶ μὴ εἰκαίᾳ σ. [Refs 5th c.BC+]: absolutely, ordinary language, ἐν τῇ σ. [Refs 1st c.AD+]; κατὰ τὴν σ. [Refs 4th c.BC+]
__III customary gratuity, [Refs 3rd c.AD+]: plural, perquisites, [Refs 4th c.AD+]

_{LSJ Scripture Refs: 1Cor.8.7}