Definition of potassium in US English:



  • The chemical element of atomic number 19, a soft silvery-white reactive metal of the alkali metal group.

    Potassium is a member of the alkali metal group, and its compounds occur widely in minerals and in seawater. The metal itself has few uses, but its compounds are used in the manufacture of fertilizers, soaps, and glass. In the body, potassium ions are involved in the transmission of nerve impulses and are an important constituent of the fluid within cells

    • ‘Sodium, potassium and blood sugar levels were estimated using standard methods.’
    • ‘Patients no longer needed extra sodium and restricted potassium.’
    • ‘If you tend to be susceptible to cramps, try eating more foods that are high in potassium and calcium.’
    • ‘In a chemical sense, soap is a salt made up of a carboxylic acid and an alkali like sodium of potassium.’
    • ‘The second most abundant ion was potassium, followed by sodium, magnesium, manganese and iron.’
    • ‘He worked on light metal alloys and the electrolytic production of potassium and sodium.’
    • ‘It is high in vitamins A and E, calcium and potassium, and low in calories.’
    • ‘Diuretics reduce fluid retention in the body by encouraging the removal of salts such as potassium and sodium from the blood.’
    • ‘It also involves the loss of important blood salts like potassium and sodium.’
    • ‘Its high potassium, phosphorus and calcium help maintain high energy levels.’
    • ‘This does not happen, however, because the cell membrane itself is impermeable to ions like sodium and potassium.’
    • ‘He says a complete plant food with plenty of trace elements especially potassium and nitrogen and water it well in.’
    • ‘In that case potassium rather than sodium is exchanged with calcium and magnesium.’
    • ‘For example, lithium, sodium, and potassium comprised a triad of soft, highly reactive metals.’
    • ‘At the same time we consume about a third less potassium, so that the ratio of potassium to sodium has shifted quite dramatically.’
    • ‘The plants are sustained by water, enriched with calcium, potassium, nitrogen and other fertilisers.’
    • ‘Calcium and potassium are two of the top nutrients of concern in Americans' diets.’
    • ‘Nitrate crusts of potassium and calcium nitrate are most often found in caves and rock shelters in limestone areas.’
    • ‘These will include blood samples to find out levels of sodium, chloride, potassium and urea.’
    • ‘He should incorporate a salad, as the magnesium and potassium will help counteract the sodium.’


Early 19th century: from potash (earlier potass, from French potasse) + -ium.