Georg Autenrieth, A Homeric Dictionary

σύν, ξύν , the latter (older) form for metrical convenience, but more freely in compounds: along with, together.— I. adv., together, at once; σὺν δὲ δύω μάρψα_ς, Od. 9.289 (cf. 311, 344); σὺν δὲ νεφέεσσι (dat. instr.) κάλυψεν | γαῖαν ὁμοῦ καὶ πόντον, Od. 5.293; ἦλθε Δολίος, σὺν δ᾽ υἱεῖς, ‘along with him,’ Od. 24.387; of mingling, confusing, breaking up, σὺν δ᾽ ἥμι_ν δαῖτα ταράξῃ, Il. 1.579 (cf. Il. 8.86); σὺν δ᾽ ὅρκἰ ἔχευαν, Il. 4.269; σὺν δὲ γέροντι νόος χύτο, Il. 24.358.—II. prep. w. dat., with, in company with, by the aid of; σὺν θεῷ, σὺν θεοῖσιν, σὺν Ἀθήνῃ, σὺν σοί, Od. 13.391; of things, with, denoting accompaniment and secondarily instrument, the clothing or armor one wears, the ship one sails with, Il. 3.29, Il. 1.179; met., of quality or characteristic, ἄκοιτιν σὺν μεγάλῃ ἀρετῇ ἐκτήσω, Od. 24.193; of consequence, penalty, σὺν δὲ μεγάλῳ ἀπέτι_σαν, Il. 4.161. σύν sometimes follows its case, Od. 15.410.