Lewis & Short

coetus, us, v. 2. coitus.

2. cŏĭtus, and another orthography coetus (only distinguished in signif. by use; v. infra), ūs (dat. coetu, Cat. 64, 385; 66, 37), m. [coëo].

  1. I. In gen.
    1. A. Abstr., a coming or meeting together, an assembling: eos auspicio meo atque ductu primo coetu vicimus, Plaut. Am. 2, 2, 25.
      Hence,
    2. B. Concr., an assemblage, crowd, company; in this signif. coetus alone is used: quae (opiniones) in senatu, quae in omni coetu concilioque profitendae sint, Cic. Fin. 2, 24, 77; 2, 4, 11; id. Rep. 6, 13, 13: ad divinum animorum concilium coetumque proficisci, id. Sen. 23, 84; id. de Or. 1, 8, 30; id. Verr. 2, 5, 72, § 186; Liv. 3, 38, 11; 27, 35, 3; Quint. 2, 15, 18; 2, 9, 2; 8, 4, 8; Cat. 46, 8; 64, 407; Verg. A. 5, 43; Ov. M. 3, 403; 11, 766; 15, 66: in domum Pisonis, Tac. A. 4, 41; id. H. 4, 45.
  2. II. Esp.
    1. A. A uniting, joining together, combination; so in both forms.
          1. (α) Coetus, Lucr. 1, 1016; 1, 1047; 2, 919; 2, 1003; 5, 429: ceterum amnium coctus maritimis similes fluctus movet, Curt. 9, 4, 9: stellarum coetus et discessiones, Gell. 14, 1, 14.
          2. (β) Coitus: ut recens coitus venae resolvatur, Cels. 2, 10 fin.: umoris, id. 5, 18, 31: sordium in auribus, id. 6, 7, 7: syllabarum, Quint. 9, 4, 59: vocum, Gell. 1, 25, 16: osculi, Poët. ap. Gell. 19, 11, 4: luna morata in coitu solis biduo (i. e. at new moon), Plin. 2, 9, 6, § 44.
    2. B. Sexual intercourse, coition (not in Cic.); in this signif. only coitus is used.
      Of men, Ov. M. 7, 709; Suet. Calig. 25; cf. Quint. 8, 6, 24; Gai Inst. 1, 64; 1, 87.
      Of animals, Col. 6, 24, 3; 6, 23, 3 (Cod. Polit. coetus); Cels. 2, 1 fin. al.
      1. 2. Transf., of plants: palmarum, Plin. 13, 4, 7, § 35.
        Also of ingrafting, Plin. 17, 14, 24, § 103.