Definition of barium in US English:



  • 1The chemical element of atomic number 56, a soft white reactive metal of the alkaline earth group.

    Barium compounds are used in water purification, the glass industry, and pigments, and as an ingredient of signal flares and fireworks, giving a bright yellowish-green color. Barium oxide is a component of high-temperature superconductors

    • ‘Nearby, there could be drums containing potassium, nickel, barium or a little bit of manganese leaching into the pretty stream.’
    • ‘Cesium - 137, which decays to nonradioactive barium, is found in spent fuel elements from nuclear reactors.’
    • ‘The lanthanides make up the elements between barium and hafnium in Row 6 of the periodic table.’
    • ‘Crawford was interested in the study of minerals and other chemicals and spent some time analyzing the mineral known as baryte, a primary source of the element barium.’
    • ‘New processing methods are outlined from which potassium, sodium, barium, strontium and cadmium were discovered.’
    • ‘This is the case for the superconducting material studied here, known as YBCO for its constituent elements: yttrium, barium, copper, and oxygen.’
    • ‘Thorium and uranium, for instance, are forged in the heat of a supernova, and barium and bismuth via the capture of neutrons within red giant stars.’
    • ‘On the site of Barium and Chemical Inc. in Steubenville, Ohio, lies an aquifer that contains chemicals such as nitrate and barium that were dumped during a time when this was a legal method of disposal.’
    • ‘If the carbon and oxygen signatures do not match a unique location, Thorrold examines trace metals like magnesium, manganese, strontium and barium to fine-tune the fish's whereabouts.’
    • ‘Many of these cavities contain good crystals of potassium, strontium, barium, rare earths, titanium, and niobium minerals.’
    • ‘Pull up a seat at this giant table - yes, it's actually a wooden periodic table - and learn more than you ever dreamed you could about calcium, helium, barium and their more exotic cousins.’
    • ‘They attempted to gauge sediment deposits over that period by measuring core-layer fluctuations in the ratio of barium to calcium.’
    • ‘The resulting elements (such as, strontium, zirconium, barium, lanthanum, and lead) then decay into still heavier elements.’
    • ‘But barium has an atomic number of 56, barely more than half that of uranium.’
    • ‘Cartridges found at the Post Office contained residues of aluminium, lead, barium and antimony or three or two of these elements.’
    • ‘He suggested the name barium for the element based on the scientific name for the Bologna stone, barite.’
    • ‘The house he had lived in, found to be contaminated with barium, would be destroyed.’
    • ‘Fireworks made with an aluminum mixture that contains barium will produce white sparks, whereas a firework made with strontium sends off red sparks.’
    • ‘Bains analysed the concentration of the element barium - a powerful tool for measuring ocean productivity - in sediments deposited across the boundary.’
    • ‘We quickly learned that those cases were from their new non-toxic primers, which contained no lead or other heavy metals such as barium and antimony.’
    1. 1.1 A mixture of barium sulfate and water, opaque to X-rays, which is swallowed to permit radiological examination of the stomach or intestines.
      as modifier ‘a barium meal’
      • ‘Useful modalities for investigating a suspected case include small bowel barium meal, barium enema, ultrasonography, computed tomographic scan and colonoscopy.’
      • ‘The index patient also infected the husband of another patient, who was waiting for his wife to undergo barium meal examination in the diagnostic radiology department, who subsequently infected his wife.’
      • ‘Gastric ulcers without any malignant characteristics seen on barium swallow have a specificity of more than 95 percent in ruling out gastric cancer.’
      • ‘A brief, limited barium swallow examination can confirm if the pouch is small or enlarged.’
      • ‘The videofluoroscopic swallowing study with barium is a multidisciplinary evaluation with collaboration between a radiologist and a speech-language pathologist.’
      • ‘A barium swallow examination disclosed a small filling defect in the lower third of the esophagus.’
      • ‘Endoscopy and barium meal are the principal investigations.’
      • ‘The barium shows up white on the x ray, allowing a clear view of the colon and will show how much of the colon is affected.’
      • ‘Some researchers suggest that diagnosis should be based on patient history and confirmed by barium swallow, and that an upper endoscopy is not indicated.’
      • ‘Reported food obstruction below the clavicles requires primary investigation with either upper gastrointestinal endoscopy or barium swallow.’
      • ‘A barium examination of the upper gastrointestinal tract showed the stricture as a filling defect.’
      • ‘Behind them was a screen showing mostly medical videos of operations, barium meals, gastroscopies, angiograms, arthroscopy, etc.’
      • ‘Patients waiting for non-urgent radiology examinations, such as CT scans, barium meals and enemas are now being assessed up to ten times quicker than two years ago.’
      • ‘Based on the patient history and physical examination, barium esophagram and/or gastroesophageal endoscopy can confirm the diagnosis.’
      • ‘A white liquid called barium is then passed through the rectum in the same way as the washout while the specialist views the bowel on an x-ray screen.’
      • ‘Few patients had endoscopy or upper gastrointestinal barium examination in the follow up year.’
      • ‘An example of this is in specialty guidelines for colon cancer screening, where radiologists recommend barium enemas while gastroenterologists recommend colonoscopy.’
      • ‘There is also insufficient evidence to recommend for or against routine screening with digital rectal examination, barium enema, or colonoscopy.’
      • ‘Suspected oesophageal strictures at endoscopy were confirmed by barium swallow examination.’
      • ‘A barium swallow can also show the refluxing of liquid into the esophagus, and it may show whether the esophagus is irritated or whether there are any physical abnormalities in the upper digestive tract.’


Early 19th century: from baryta + -ium.