Definition of colloid in US English:



  • 1A homogeneous noncrystalline substance consisting of large molecules or ultramicroscopic particles of one substance dispersed through a second substance. Colloids include gels, sols, and emulsions; the particles do not settle, and cannot be separated out by ordinary filtering or centrifuging like those in a suspension.

    • ‘In lyophobic colloids the particle-solvent interaction is energetically unfavorable and the suspension will sooner or later separate.’
    • ‘He showed that these materials were long, chain-like molecules and not colloids as previously thought.’
    • ‘This increase in cytoplasmic viscosity can be described as a sol-gel transition, which is generally explained with chemical or physical reactions of molecules, polymers, or colloids.’
    • ‘By depositing proteins as monolayers onto gold colloids, the aim will be to develop biosensors for nitrate and nitric oxide with detection capabilities approaching those of natural bacterial cells.’
    • ‘And 10 years later he used freezing point depressions to determine the molecular weights of colloids such as gum, Fe 3 etc.’
    mixture, mix, blend, compound, suspension, tincture, infusion, emulsion, gel, fluid
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    1. 1.1Anatomy Medicine A substance of gelatinous consistency.
      • ‘These techniques offer advantages similar to those of haemodilution but do not require infusions of crystalloid or colloid to preserve blood volume.’
      • ‘Radiolabeled colloid injected into the peritoneal cavity can be used to demonstrate the communication between the peritoneal and pleural space.’
      • ‘The most common radiotracers used in GI bleeding studies are 99m-Tc labeled red blood cells and 99m-Tc sulfur colloid.’
      • ‘Cell blocks revealed sheets or clusters of follicular cells and variably sized follicles filled with colloid.’
      • ‘Thus, sentinel lymph nodes can be detected by the injection of blue dye or radioactive colloid around the tumor, which travels to and identifies the first draining sentinel lymph node.’


  • attributive Of the nature relating to or characterized by a colloid or colloids.

    • ‘Several previous reports have dealt with the experimental and theoretical aspects of depletion aggregation, often termed depletion flocculation, as applied to the general field of colloid chemistry.’
    • ‘This assumption is generally verified in colloid science and has been precisely verified for our material only at low concentration of monovalent salt.’
    • ‘The addition of neutral polymers to colloid solutions results in a nonspecific attractive potential between colloids, called the depletion attraction, dependent upon polymer size and concentration.’
    • ‘They attributed their low colloid carcinoma detection rate to the absence of sufficient guidelines for the identification of colloid carcinoma at the time of their study.’
    • ‘The first cancer had been diagnosed as colloid carcinoma in 1985.’


Mid 19th century: from Greek kolla ‘glue’ + -oid.