scapula

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Either of two large, flat, triangular bones forming the back part of the shoulder. Also called shoulder blade.

Century Dictionary and Cyclopedia

1. n. In anatomy, the shoulder-blade, or blade-bone, or omoplate. It is the proximal element of the pectoral or scapular arch of vertebrates, especially of higher vertebrates, in which it is primitively the proximal part of a cartilaginous rod, the distal part of which is segmented off to form the coracoid. It assumes the most various shapes in different animals, but is usually flattened and expansive in mammals, in birds slender and saber-like. The scapula, whatever its shape, normally maintains connection with the coracoid, which is then a separate bone, but in all mammals above the monotremes the coracoid is completely consolidated with the scapula, appearing as a mere process of the latter. The human, like other mammalian scapulæ, with the exception noted, is therefore a compound bone, consisting of scapula and coracoid united. The scapula, or scapula and coracoid together, normally furnish an articulation for the clavicle when the latter is fully developed. In mammals above monotremes this articulation is with the spine or acromion. The glenoid cavity for the articulation of the humerus is always at the junction of the scapula proper with the coracoid, and when the latter is separate both bones enter into its formation. Morphologically a well-developed scapula, as in a mammal, has two ends, three borders, and three surfaces, corresponding to the prismatic rod of primitive cartilage; these parts, however, do not correspond with the borders, angles, and surfaces described in human anatomy (for which see shoulder-blade), the vertebral border, for instance, being really one end of the bone, and the edge of the spine being one of the morphological borders. The three surfaces correspond to the supraspinous, infraspinous, and subscapular fossæ, better known as the prescapular, postscapular, and subscapular surfaces. In all mammals and birds, and most reptiles proper, the scapula closely conforms to the characters here given. In batrachians and fishes, however, whose scapular arch is complicated with additional bones, the modifications are various, and some of the coracoid elements have been wrongly regarded and named as scapular. See cuts under omosternum, scapulocoracoid, and shoulder-blade. See also postscapular, prescapular, subscapular, suprascapular.
2. n. In Crinoidea, one of the plates in the cup which give rise to the arms.
3. n. In entomology: One of the parapsides or plicæ scapulares on the side of the mesothorax.
4. n. A pleura, including the episternum and epimeron, the latter being distinguished by Burmeister as the posterior wing of the scapula. Also scapularium. See parapsis.
5. n. A shoulder-tippet, or shoulder-cover. See patagium .
6. n. A trochanter of the fore leg.

Wiktionary

1. n. anatomy Either of the two large, flat, bones forming the back of the shoulder.

GNU Webster's 1913

1. n. (Anat.) The principal bone of the shoulder girdle in mammals; the shoulder blade.
2. n. (Zoöl.) One of the plates from which the arms of a crinoid arise.

WordNet 3.0

1. n. either of two flat triangular bones one on each side of the shoulder in human beings