Definition of plasma in US English:


(also plasm)


  • 1The colorless fluid part of blood, lymph, or milk, in which corpuscles or fat globules are suspended.

    • ‘Blood is made up of plasma, red blood cells, white blood cells and platelets.’
    • ‘Furthermore, urea readily diffuses between the plasma and airway fluid.’
    • ‘Instead, blood is often separated into its three main components; red blood cells, plasma, and platelets.’
    • ‘The rest of the space is taken up by plasma, white blood cells, platelets, clotting factors and other miscellaneous molecules.’
    • ‘One of the two key findings of the study was a consistent gradient of cytokine concentration, with the highest levels found in ascitic fluid followed by lymph and then plasma.’
    • ‘Lysed erythrocytes, blood plasma, and damaged lung tissue were discussed as possible sources for the cholesterol and its esters.’
    • ‘These cells travel through the circulatory system suspended in a yellowish fluid called plasma (pronounced: plaz muh).’
    • ‘The use of smaller VTS in humans leads to reduced concentrations of polymorphonuclear cells and cytokines in both plasma and bronchoalveolar lavage fluid.’
    • ‘Globally, the cytokine profile showed a parallel time course in plasma and lymph.’
    • ‘The tattoo is again sprayed and cleaned and pressure is applied using a disposable towel to remove any blood and plasma excreted during the tattooing process.’
    • ‘The HIV bDNA assays can be used for the detection and quantification of HIV virions in plasma, serum, blood cells, or tissue.’
    • ‘It is composed of: red corpuscles, white cells, platelets, and blood plasma.’
    • ‘During plasma exchange treatment, the patient's blood is removed and the blood cells are mechanically separated from the fluid plasma.’
    • ‘Additionally, interstitial fluid and blood plasma contain some non-electrolytes such as glucose.’
    • ‘Cortisol levels can be determined from plasma, urine, and saliva samples.’
    • ‘Dehp migrates into a variety of fluids including blood, plasma, and total parenteral and enterai nutrition solutions.’
    • ‘It is comprised of a network of ducts, called lymph vessels or lymphatics, and carries lymph, a clear, watery fluid that resembles the plasma of blood.’
    • ‘If the drug concentrations in plasma or other body fluids decrease mono-exponentially in time, absorption is apparently absent or very fast.’
    • ‘Despite inhibition of viral replication in plasma, lymph nodes, and at other sites, reservoirs of HIV infection in latently infected resting T lymphocytes remain.’
    • ‘To answer this question, they first compared the levels of thrombin-activatable fibrinolysis inhibitor in bronchoalveolar fluid and in plasma.’
  • 2An ionized gas consisting of positive ions and free electrons in proportions resulting in more or less no overall electric charge, typically at low pressures (as in the upper atmosphere and in fluorescent lamps) or at very high temperatures (as in stars and nuclear fusion reactors)

    ‘the current passed through a column of plasma’
    as modifier ‘plasma physics’
    • ‘The Stevens plasma reactor is more energy efficient than conventional devices and does not require a carrier gas to remain stable at atmospheric pressure.’
    • ‘The photons can break apart, or ionize, molecules and atoms of the atmosphere into protons and electrons, producing plasma.’
    • ‘Newer methods of sterilization include alternatives to ethylene oxide, such as low temperature hydrogen peroxide gas plasma and peracetic acid.’
    • ‘Research on nuclear fusion in the 1940s shifted the focus of plasma research from the stars to laboratories on Earth.’
    • ‘In fact, the whole magnetosphere becomes a hotter place as the energy of the CME increases plasma temperatures.’
    • ‘For example, in discussing ionized plasma boundary layer control, a certain paper by engineers at Northrop is mentioned.’
    • ‘Magnetic reconnection should produce telltale jets of moving plasma at high temperature that we hope to detect with EIS.’
    • ‘‘That gives higher temperatures and plasma densities even than H-mode,’ he says.’
    • ‘The difference is that those field lines are enmeshed within the electrically charged, superheated plasma that comprises the body of the Sun.’
    • ‘Parts are placed in a quartz glass container that is used to contain the plasma at atmospheric pressure once the container has been purged of air through the introduction of argon.’
    • ‘This expansion of the atmosphere significantly increases the number of microscopic collisions between the satellite and the gases and plasma of the upper atmosphere.’
    • ‘Warp reactors both show good plasma flow, and are building up neutrons now.’
    • ‘In addition to hydrostatic pressure, GFR is influenced by glomerular plasma osmotic pressure.’
    • ‘This results in a plasma of free protons and electrons.’
    • ‘To produce useful amounts of energy from fusion on earth, scientists must produce a plasma with the required temperature, density, and heat retention.’
    • ‘After the gas reaches a certain temperature it becomes plasma.’
    • ‘Depending on a plasma's temperature and its mix of atoms, some free electrons will recombine with needy atoms and cascade down the myriad energy levels within.’
    • ‘It is the understanding of these expansion dynamics that is exciting, because it may be that ultracold plasmas cross over to the regime of strongly coupled plasma physics.’
    • ‘If plasma at that temperature so much as touched anything, it would go out like a light.’
    • ‘Venus Express will be positioned to map the background magnetic field in the region, to track how the solar plasma interacts with the atmosphere.’
    1. 2.1 An analogous substance consisting of mobile charged particles (such as a molten salt or the electrons within a metal).
      • ‘However, shielded metal arc welding, plasma arc, and electron beam welding processes can be used.’
      • ‘This creates an electrically charged, superheated plasma of iron atoms that bonds to the surface as a new substance.’
      • ‘The device works by creating an electrical charge through a stream of ionized gas, or plasma.’
      • ‘The team grew the nano-needles by saturating droplets of molten gold with zinc oxide plasma.’
      • ‘They used energetic particles in a plasma to knock, or sputter, carbon atoms from a graphite surface, forming a carbon vapor.’
      • ‘Due to its lower flame temperature and particle velocity compared with plasma spraying, flame spraying produces a less dense coating having lower adhesion strength.’
      • ‘For gas tungsten arc and plasma arc the filler metals are not used and the edges are fused.’
      • ‘As plasma is a mixture of positive and negative particles, magnetic fields may be used to contain it and prevent the particles hitting the wall of the containing vacuum vessel.’
  • 3A dark green, translucent variety of quartz used in mosaic and for other decorative purposes.

    • ‘Plasma is sometimes considered a green variety of jasper, and sometimes considered as a green and translucent variety of chalcedony.’
  • 4

    another term for cytoplasm or protoplasm
    • ‘(C and D) CG14217 is present at high levels in the pole plasm and is taken up by the pole cells.’
    • ‘Transgenic flies were then produced using the standard embryo pole plasm injection technique.’
    • ‘Scattered throughout the plasma in cells are organelles called mitochondria.’
    • ‘First, we have checked that in K + buffer plasma and mitochondrial potentials were dissipated.’
    • ‘In photosynthetic eukaryotic organisms, nitrate assimilation involves two membrane barriers, the plasma and the chloroplast membranes.’
    • ‘The DNA sequences used were isolated from either plasma RNA or peripheral blood mononuclear cells.’
    • ‘Aquaporins are water channel proteins that are expressed in various membrane compartments of plant cells, including the plasma and vacuolar membranes.’
    • ‘Analysis of homozygous germline clones can be employed to reveal the role of pleiotropic genes in pole plasm formation.’


Early 18th century (in the sense ‘mold, shape’): from late Latin, literally ‘mold’, from Greek plasma, from plassein ‘to shape’.