skull

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The bony or cartilaginous framework of the head of vertebrates, made up of the bones of the braincase and face; cranium.
2. n. Informal The head, regarded as the seat of thought or intelligence: Use your skull and solve the problem.
3. n. A death's-head.

Century Dictionary and Cyclopedia

1. n. A bowl; a bowl to hold liquor; a goblet.
2. n. The cranium; the skeleton of the head; the bony or cartilaginous framework of the head, containing the brain and supporting the face. A skull is possessed by all vertebrates excepting the lancelets, and by no other animals. It is sometimes divided into the skull proper, cranium in strictness or brain-box, and the facial region or face. In the adult human skull eight cranial and fourteen facial bones are commonly enumerated, though the real number of osseous elements is much larger. The eight cranial bones are the occipital, two parietal, two temporal, frontal, sphenoid, and ethmoid. The fourteen facial bones are two nasals, two lacrymals, two superior maxillaries, two malars, two palatals, two inferior turbinals, one inferior maxillary, and one vomer. This enumeration of the bones is exclusive of the bonelets of the ear, which, however, are counted in vertebrates below mammals. Of these bones, the mandible, vomer, and frontal are really paired, or of lateral halves; the supramaxillary, ethmoid, sphenoid, occipital, and temporal are compound bones of several separate centers of ossification; the rest are simple. The most composite bone is the temporal, whose ankylosed stylohyoid process (peculiar to man) is an element of the hyoid arch. A skull of similar construction characterizes mammals at large, though its figure is usually quite different (owing mainly to production of the facial and reduction of the cranial parts), and though some of the bones which are confluent in man may remain distinct. In birds the skull is characterized by the great size of the cranial bones in comparison with that of the facial bones (excepting the specially enlarged intermaxillary and inframaxillary), the extensive and complete ankyloses of cranial bones, the permanent and perfect distinctness of pterygoid bones, the formation of each half of the lower jaw by several recognizable pieces, and especially by the intervention of a movable quadrate bone between the squamosal and the mandible. Some other additional bones make their appearance; and the occipital condyle is always single. A skull of similar construction to that of birds characterizes reptiles proper; but here again the cranial is small in comparison with the facial region (as in the lower mammals), sometimes excessively so; the skull is more loosely constructed, with fewer ankyloses of its several elements; and some additional bones not found in any higher vertebrates first appear. The skulls of batrachians differ widely from all the above. Some additional elements appear; some usually ossified elements may be persistently cartilaginous; and branchial as well as hyoidean arches are seen to be parts of the skull. The further modifications of the skull in fishes are great and diversified: not only is there much variation in the skulls of different fishes, but also the difference between any of their skulls and those of higher vertebrates is so great that some of the bones can be only doubtfully homologized with those of higher vertebrates, while of others no homologues can be recognized. In these ichthyopsidan vertebrates, also, the skull is sometimes permanently cartilaginous, as in selachians; in the lampreys the lower jaw disappears; in the lancelets there is no skull. In fislies, also, more or fewer branchial arches are conspicuous parts of the skull, forming usually, with the compound lower jaw, by far the bulkier section of this collection of bones; and in some of them the connection of the shoulder-girdle with the skull is such that it is not always easy to say of certain bones whether they are more properly scapular or cranial. The natural evolution of the skull is, of course, from the lower to the higher vertebrates (the reverse of that above sketched). Above lampreys and hags, after a lower jaw has been acquired, the general course of evolution of the skull is to the reduction in number of its bones or cartilages by the entire disappearance of some and the confluence of others, tending on the whole to the compactness, simplicity, and symmetry of which the human skull is the extreme case, and in which, as in the skull of any mammal or bird, evidences of its actual osseous elements are chiefly to be traced in the transitory centers of ossification of the embryo. A good illustration of this is witnessed in the condition of the bones of the tongue (hyoid arch) in mammals; for even in birds (next below mammals) the tongue has a skeleton of several distinct bones, the position of which in a series of arches next after the mandibular and next before the branchial arches proper is evident. The base of the skull is generally laid down in cartilage. The dome of the skull and the facial parts are usually of membrane-bones; and to the latter some dermal or exoskeletal bones may be added. Facial parts of all skulls are of different character from cranial parts proper, in that they belong essentially to the series of visceral (hemal, not neural) arches: upper jaw; under jaw; tongue (hyoid), followed by more or fewer successive branchial arches. The neural arches, or cranial segments proper, are at least 3 (some count 4) in number, named occipital, parietal, and frontal, from behind forward, represented respectively by the occipital bone; the basisphenoid, alisphenoid, and parietal bones; the presphenoid, orbitosphenoid, and frontal bones. With these are intercalated or connected the sense-capsules of the three higher senses—namely, of hearing, sight, and smell—these being the skeletons of the ear, eye, and nose, or the petrosal parts of the temporal, the sclerotic coat of the eye, and the lateral masses of the ethmoid bone. Remaining hard parts of the head, and, as such, elements of the skull, are the teeth, borne on more or fewer bones; in mammals, when present, confined to the premaxillaries, supramaxillaries, and inframaxillaries; not present in any existing birds; in various reptiles and fishes, absent, or borne upon the bones above named, and also, in that case, upon the sphenoid, vomer, palatals, pterygoids, hyoids, pharyngeals, etc. The body of facts or principles concerning skulls is craniology, of which craniometry is one department, especially applied to the measurement of human skulls for the purposes of ethnography or anthropology. For the human skull (otherwise than as here figured), see cuts under craniofacial, craniometry, cranium, ear, nasal, orbit, palate, parietal, and skeleton. For various other mammalian skulls, see cuts under Balænidæ, Canidæ, castor, Catarrhina, Edentata, Elephantinæ, Equidæ, Felidæ, Leporidæ, Mastodontinæ, Muridæ, ox, physeter, Pteropodidæ, ruminant, skeleton. Birds' skulls, or parts of them, are figured under chondrocranium, desmognathous, diploë, dromæognathous, Gallinæ, Ichthyornis, quadrate, salivary, saurognathous, schizognathous, schizorhinal, sclerotal; reptiles', under acrodont, Chelonia, Crocodilia, Crotalus, Cyclodus, Ichthyosauria, Ichthyosaurus, Mosasaurus, Ophidia, periotic, Plesiosaurus, pleurodont, pterodactyl, Pythonid æ; batrachians', under Anura, girdle-bone, Rana; fishes', under Acipenser, Esox, fish, Lepidosiren, palatoquadrate, parasphenoid, Petromyzon, Spatularia, Squatina, teleost. The absence of a skull appears under Branchiostoma and Pharyngobranchii. The homology of several visceral arches is shown under hyoid.
3. n. The head as the seat of intelligence; the sconce or noddle: generally used disparagingly.
4. n. In armor, that part of a head-piece which covers the crown or the head, especially in the head-pieces made up of many parts, such as the armet. See cut under secret.
5. n. A large shallow basket without a bow-handle, used for carrying fruit, potatoes, fish, etc.
6. n. In metallurgy, the crust which is formed by the cooling of a metal upon the sides of a ladle or any vessel used for containing or conveying it in a molten condition. Such a crust or skull is liable to form on the Bessemer converter when the blowing has been continued beyond the point of entire decarburization.
7. n. See scull.
8. n. An obsolete form of school.
9. n. The common skua, Megalestris skua. Also scull.
10. n. The trade-name for the anterior plate of the carapace of the hawk's-bill turtle, which yields the tortoise-shell of commerce.

Wiktionary

1. n. anatomy The main bones of the head considered as a unit; the cranium.
2. n. A symbol for death; death's-head
3. v. To hit in the head with a fist, a weapon, or a thrown object.

GNU Webster's 1913

1. n. obsolete A school, company, or shoal.
2. n. (Anat.) The skeleton of the head of a vertebrate animal, including the brain case, or cranium, and the bones and cartilages of the face and mouth. See Illusts. of carnivora, of Facial angles under facial, and of Skeleton, in Appendix.
3. n. The head or brain; the seat of intelligence; mind.
4. n. Obs. & R. A covering for the head; a skullcap.
5. n. A sort of oar. See Scull.

WordNet 3.0

1. n. the bony skeleton of the head of vertebrates