Henry George Liddell, Robert Scott, A Greek-English Lexicon

A.union, E.HF675 (lyr.); union of branches with the trunk, “ς. τῶν φλεβῶν” Arist.HA586b21.

II. yoke of animals, pair, “ς. πώλων” E.Hipp.1131 (lyr.); of persons, Plu.Demetr.1: generally, pair, Pl. Phd.71c, Prm.143d, Arist.IA704b20; ς. πτερύγων, μήλων, δονάκων, AP5.267.6, 289 (both Paul. Sil.), 6.27 (Theaet.); ἄρσενα ς., of two sons, IG12(8).442.6 (Thasos); κατὰ συζυγίας in pairs, esp. of animals, “κατὰ συζυγίας φωλοῦσιν . . οἱ ἄρρενες θήλεσιν” Arist.HA599b6, cf. 631b1; in plants, Thphr.HP3.11.3, al.: hence,

2. coupling, copulation, AP5.220 (Paul. Sil.), 10.68 (Agath.).

3. in war, squadron of four war-chariots,= two ζυγαρχίαι, Ascl.Tact.8, Ael. Tact.22.2.

III. conjunction of words or things in pairs, syzygy, Arist.Top.113a12, GC332b3 (pl.), Mete.378b11 (pl.), Stoic.2.132, Gal. 6.95, al.: more generally, combination of words, οὐκ ἐν τῷ κάλλει τῶν ὀνομάτων ἡ πειθώ, ἀλλ᾽ ἐν τῇ ς. D.H.Comp.3, cf. 6; of letters, ib.22; coupling of terms in a syllogism, Chrysipp.Stoic.2.50.

2. Gramm., conjugation, D.T.638.6 (pl.), A.D.Adv.161.28, POxy.469.13 (iii A.D.); or declension, A.D.Adv.198.6, Synt.271.16, Ath.9.392b; any group of related words, e.g. sapiens, sapienter, sapientia, Cic.Top. 3.12, cf. 9.38.

3. in Prosody, syzygy, dipodia, Heph.7.8, Aristid. Quint.1.14, Syrian.in Hermog.1p.31R.

b. syncope, Anon.Rhythm. 3.19.

IV. Astron., syzygy, of two stars one of which rises and sets as the other sets and rises, Autol.1.4; of zodiacal signs rising and setting between the same points of the horizon, Gem.2.27; of the moon's conjunctions and oppositions with the sun, Ptol.Alm. 5.1, Cat.Cod.Astr.1.131; so of planets, Ptol.Alm.5.10.

V. Math., αἱ κατὰ συζυγίαν ἀντικείμεναι [τομαί] conjugate opposite sections, i.e. conjugate hyperbolas, each with two branches, Apollon.Perg.Con. 2.17, al.