a. (sb.) Anat. Also erron. 8–9 xyphoid, 9 ziphoide. [ad. mod.L. xiphoidēs, a. Gr. ξιφοειδής f. ξίφος sword + εἶδος form: see -OID.] Sword-shaped, ensiform: a descriptive epithet of the cartilaginous or bony process at the lower or posterior end of the sternum in man and other animals (also called XIPHISTERNUM), and of a projecting bone at the back of the head in the cormorants and related birds (also called occipital style).
1746. Glass, Dropsy, in Phil. Trans., XLIV. 338. We found the Circumference of her Abdomen to be just six Feet four Inches, and from the Xyphoid Cartilage to the Os Pubis it measur’d four Feet and half an Inch.
1782. A. Monro, Anat., 172. The outer surface of the xiphoid bone.
1802. Home, in Phil. Trans., XCII. 351. In the Hystrix, there is a xiphoid cartilage.
1847–9. Todd’s Cycl. Anat., IV. 202/1. [The sternum] is connected … with a xyphoid appendix.
1848. Dunglison, Med. Lex. (ed. 7), Xiphoid ligament … is a small, very thin, ligamentous fasciculus, which passes from the cartilage … of the 7th rib to the anterior surface of the xiphoid cartilage.
1873. Mivart, Elem. Anat., 35. The narrow lower end [of the sternum], which projects freely and remains cartilaginous till late in life, is called the xiphoid process. Ibid., 65. In Frogs and Toads we have a middle and xiphoid sternum.
So Xiphoidal, Xiphoidan, Xiphoidian adjs.
1653. R. Sanders, Physiogn., 276. The brest … extended from the throat to the Diaphragma or Cartilagian Xiphoidan muscle or Midriff, which is round, lying overthwart the lower part of the brest, separating the heart and lights from the stomach.
1860. Mayne, Expos. Lex., 1345/2. Xiphoidian.
1904. Amer. Nat., Jan., 20. (Osteology of Pygopodes) A pair of flaring external xiphoidal processes, which curve outwards, then inwards.
