os

Other forms: ora; ossa; osar

Definitions of os

1. noun

   a mouth or mouthlike opening
   type of:

   opening, orifice, porta

   an aperture or hole that opens into a bodily cavity
2. noun

   rigid connective tissue that makes up the skeleton of vertebrates
   synonyms: bone

   types:

   furcula

   a forked bone formed by the fusion of the clavicles of most birds

   splint bone

   a rudimentary metacarpal or metatarsal bone on either side of the cannon bone in the leg of a horse or related animal

   fetter bone, pastern

   the part between the fetlock and the hoof

   cannon bone

   greatly developed metatarsal or metacarpal bone in the shank or cannon part of the leg in hoofed mammals

   fishbone

   a bone of a fish

   anklebone, astragal, astragalus, talus

   the bone in the ankle that articulates with the leg bones to form the ankle joint

   bare bone

   bone stripped of flesh

   cuboid bone

   the cube shaped bone on the outer side of the tarsus

   carpal, carpal bone, wrist bone

   any of the eight small bones of the wrist of primates

   cartilage bone

   any bone that develops within cartilage rather than a fibrous tissue

   centrum

   the main body of a vertebra

   cheekbone, jugal bone, malar, malar bone, os zygomaticum, zygomatic, zygomatic bone

   the arch of bone beneath the eye that forms the prominence of the cheek

   clavicle, collarbone

   bone linking the scapula and sternum

   coccyx, tail bone

   the end of the vertebral column in humans and tailless apes

   dentin, dentine

   bone (calcified tissue) surrounding the pulp cavity of a tooth

   ethmoid, ethmoid bone

   one of the eight bones of the cranium; a small bone filled with air spaces that forms part of the eye sockets and the nasal cavity

   calcaneus, heelbone, os tarsi fibulare

   the largest tarsal bone; forms the human heel

   hipbone, innominate bone

   large flaring bone forming one half of the pelvis; made up of the ilium and ischium and pubis

   hyoid, hyoid bone, os hyoideum

   a U-shaped bone at the base of the tongue that supports the tongue muscles

   ilium

   the upper and widest of the three bones making up the hipbone

   ischial bone, ischium, os ischii

   one of the three sections of the hipbone; situated below the ilium

   long bone, os longum

   in limbs of vertebrate animals: a long cylindrical bone that contains marrow

   ramus

   the posterior part of the mandible that is more or less vertical

   membrane bone

   any bone that develops within membranous tissue without previous cartilage formation; e.g. the clavicle and bones of the skull

   metacarpal, metacarpal bone

   any bone of the hand between the wrist and fingers

   metatarsal

   any bone of the foot between the ankle and the toes

   nasal, nasal bone, os nasale

   an elongated rectangular bone that forms the bridge of the nose

   bonelet, ossicle, ossiculum

   a small bone; especially one in the middle ear

   os palatinum, palatine, palatine bone

   either of two irregularly shaped bones that form the back of the hard palate and helps to form the nasal cavity and the floor of the orbits

   phalanx

   any of the bones of the fingers or toes

   os pubis, pubic bone, pubis

   one of the three sections of the hipbone; together these two bones form the front of the pelvis

   costa, rib

   any of the 12 pairs of curved arches of bone extending from the spine to or toward the sternum in humans (and similar bones in most vertebrates)

   round bone

   bones that are round in shape

   sacrum

   wedge-shaped bone consisting of five fused vertebrae forming the posterior part of the pelvis; its base connects with the lowest lumbar vertebra and its tip with the coccyx

   scapula, shoulder blade, shoulder bone

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

   os sesamoideum, sesamoid, sesamoid bone

   any of several small round bones formed in a tendon where it passes over a joint

   os breve, short bone

   a bone that is of approximately equal dimension in all directions

   os sphenoidale, sphenoid, sphenoid bone

   butterfly-shaped bone at the base of the skull

   breastbone, sternum

   the flat bone that articulates with the clavicles and the first seven pairs of ribs

   corpus sternum, gladiolus

   the large central part of the breastbone

   manubrium

   the upper part of the breastbone

   xiphisternum, xiphoid process

   smallest of the three parts of the breastbone; articulates with the corpus sternum and the seventh rib

   tarsal, tarsal bone

   any bone of the tarsus

   os temporale, temporal bone

   a thick bone forming the side of the human cranium and encasing the inner ear

   tooth

   hard bonelike structures in the jaws of vertebrates; used for biting and chewing or for attack and defense

   turbinal, turbinate, turbinate bone

   any of the scrolled spongy bones of the nasal passages in man and other vertebrates

   tympanic bone

   the bone enclosing the middle ear

   vertebra

   one of the bony segments of the spinal column

   arcus zygomaticus, zygoma, zygomatic arch

   the slender arch formed by the temporal process of the cheekbone that bridges to the zygomatic process of the temporal bone

   modiolus

   the central conical bony pillar of the cochlea

   lacrimal bone

   small fragile bone making up part of the front inner walls of each eye socket and providing room for the passage of the lacrimal ducts

   skull

   the bony skeleton of the head of vertebrates

   calvaria, skullcap

   the dome of the skull

   braincase, brainpan, cranium

   the part of the skull that encloses the brain

   occiput

   back part of the head or skull

   sinciput

   the front part of the head or skull (including the forehead)

   jaw

   the part of the skull of a vertebrate that frames the mouth and holds the teeth

   vomer

   thin trapezoidal bone of the skull forming the posterior and inferior parts of the nasal septum

   Wormian bone, sutural bone

   any of the tiny soft bones found in the sutures between cranial bones

   marrowbone

   a bone containing edible marrow; used especially in flavoring soup

   fang

   hollow or grooved tooth of a venomous snake; used to inject its poison

   tusk

   a long pointed tooth specialized for fighting or digging; especially in an elephant or walrus or hog

   conodont

   the tiny fossil cone-shaped tooth of a primitive vertebrate of order Conodonta

   wishbone, wishing bone

   the furcula of a domestic fowl

   nasal concha

   one of several turbinate bones in the nasal cavity

   navicular, os scaphoideum, scaphoid bone

   the largest wrist bone on the thumb side

   lunate bone, os lunatum, semilunar bone

   one of the eight small wrist bones

   cuneiform bone, os triquetrum, pyramidal bone, triquetral, triquetral bone

   a wrist bone that articulates with the pisiform and hamate and lunate bones

   os pisiforme, pisiform, pisiform bone

   a small wrist bone that articulates only with the triquetral

   os trapezium, trapezium, trapezium bone

   the wrist bone on the thumb side of the hand that articulates with the 1st and 2nd metacarpals

   os trapezoideum, trapezoid, trapezoid bone

   the wrist bone between the trapezium and the capitate bones

   capitate, capitate bone, os capitatum

   the wrist bone with a rounded head shape that articulates with the 3rd metacarpus

   hamate, hamate bone, os hamatum, unciform bone

   the wrist bone in line with the 4th and 5th fingers

   jawbone, jowl, lower jaw, lower jawbone, mandible, mandibula, mandibular bone, submaxilla

   the jaw in vertebrates that is hinged to open the mouth

   auditory ossicle

   ossicles of the middle ear that transmit acoustic vibrations from the eardrum to the inner ear

   kneecap, kneepan, patella

   a small flat triangular bone in front of the knee that protects the knee joint

   chopper, pearly

   informal terms for a human `tooth'

   carnassial tooth

   the last upper premolar and first lower molar teeth of a carnivore; having sharp edges for cutting flesh

   maxilla, maxillary, upper jaw, upper jawbone

   the jaw in vertebrates that is fused to the cranium

   anterior, front tooth

   a tooth situated at the front of the mouth

   back tooth, posterior

   a tooth situated at the back of the mouth

   malposed tooth

   a tooth that has grown in a faulty position

   adult tooth, permanent tooth

   any of the 32 teeth that replace the deciduous teeth of early childhood and (with luck) can last until old age

   baby tooth, deciduous tooth, milk tooth, primary tooth

   one of the first temporary teeth of a young mammal (one of 20 in children)

   canine, canine tooth, cuspid, dogtooth, eye tooth, eyetooth

   one of the four pointed conical teeth (two in each jaw) located between the incisors and the premolars

   bicuspid, premolar

   a tooth having two cusps or points; located between the incisors and the molars

   incisor

   a tooth for cutting or gnawing; located in the front of the mouth in both jaws

   grinder, molar

   grinding tooth with a broad crown; located behind the premolars

   forehead, frontal bone, os frontale

   the large cranial bone forming the front part of the cranium: includes the upper part of the orbits

   parietal bone

   either of two skull bones between the frontal and occipital bones and forming the top and sides of the cranium

   occipital bone

   a saucer-shaped membrane bone that forms the back of the skull

   chop

   a jaw

   cervical vertebra, neck bone

   one of 7 vertebrae in the human spine located in the neck region

   dorsal vertebra, thoracic vertebra

   one of 12 vertebrae in the human vertebral column; thoracic vertebrae extend from the seventh cervical vertebra down to the first lumbar vertebra

   lumbar vertebra

   one of 5 vertebrae in the human vertebral column; lumbar vertebrae extend from the twelfth thoracic vertebra down to the sacral vertebrae

   sacral vertebra

   one of 5 vertebrae in the human spine that fuse in the adult to form the sacrum

   caudal vertebra, coccygeal vertebra

   one of 4 vertebrae in the human coccyx

   true rib

   one of the first seven ribs in a human being which attach to the sternum

   epiphysis

   the end of a long bone; initially separated from the main bone by a layer of cartilage that eventually ossifies so the parts become fused

   diaphysis, shaft

   the main (mid) section of a long bone

   arm bone

   a bone in the arm

   leg bone

   a bone of the leg

   type of:

   connective tissue

   tissue of mesodermal origin consisting of e.g. collagen fibroblasts and fatty cells; supports organs and fills spaces between them and forms tendons and ligaments