Lewis & Short

praecordĭa, ōrum (sing. praecordium, Isid. 10, 102), n. [prae-cor].

  1. I. Lit., the muscle which separates the heart and lungs from the abdomen, the midriff, diaphragm: exta homini ab inferiore viscerum parte separantur membrana, quae praecordia appellant, quia cordi praetenditur, quod Graeci appellaverunt φρένας, Plin. 11, 37, 77, § 197: (Plato) cupiditatem subter praecordia locavit, Cic. Tusc. 1, 10, 20: unius praecordia pressit senis, i. e. stopped his breath, Juv. 6, 621.
  2. II. Transf.
    1. A. The entrails, the stomach (syn.: viscera, exta, ilia): praecordia vocamus uno nomine exta in homine, Plin. 30, 5, 14, § 42; Cels. 4, 1: ipse anulus in praecordiis piscis inventus est, Cic. Fin. 5, 30, 92: totis praecordiis stertens, M. Cael. ap. Quint. 4, 2, 123; Plin. 26, 7, 19, § 35: quid veneni saevit in praecordiis, Hor. Epod. 3, 5: mulso proluere, id. S. 2, 4, 26.
    2. B. The breast, the heart (mostly poet.): spiritu remanente in praecordiis, Liv. 42, 16: frigidus coit in praecordia sanguis, Verg. A. 10, 452; Ov. M. 12, 140.
      As the seat of the feelings and passions: quondam etiam victis redit in praecordia virtus, Verg. A. 2, 367: meis inaestuat praecordiis Libera bilis, Hor. Epod. 11, 15: verax aperit praecordia Liber, id. S. 1, 4, 89: inquieta, id. Epod. 5, 95: flagrantia, Juv. 13, 102; cf.: tacita sudant praecordia culpa, id. 1, 167: mutare praecordia, i. e. sententiam, Prop. 2, 3, 13 (2, 4, 31): in praecordiis meis de mane vigilabo ad te, Vulg. Isa. 26, 9.
      Hence, even, praecordia mentis, the seat of the mind, for the mind, Ov. M. 11, 149.
    3. * C. The body, bodies in gen.: in terrā ponunt praecordia, Ov. M. 7, 559.