Definition of cyst in English:



  • 1Biology
    A thin-walled hollow organ or cavity in an animal or plant, containing a liquid secretion; a sac, vesicle, or bladder.

    • ‘The epithelial cells lining the cyst contained abundant mucin vacuoles that filled the cytoplasm of the luminal half of the cells.’
    • ‘In the lumen of the cysts, eosinophilic or blue secretions were frequently seen, with sometimes targetoid secretion.’
  • 2Medicine
    A membranous sac or cavity of abnormal character in the body, containing fluid.

    • ‘These pimples vary according to the severity of the acne and range from whiteheads, blackheads, pustules, nodules to cysts.’
    • ‘Using tiny surgical tools attached to the laparoscope, the surgeon can make a small cut in the cyst to drain the fluid away.’
    • ‘The walls of the cysts were mostly membranous with variable thickness.’
    • ‘Complications include rupture of the cyst into the peritoneal cavity, which results in urticaria, anaphylactic shock, eosinophilia, and implantation into the omentum and other viscera.’
    • ‘In a molar pregnancy, the early placenta grows abnormally into a mass of cysts.’
    • ‘We removed an aspergilloma located in the right lower lobe of the lung in a 48-year-old woman with a bronchial cyst and rheumatoid arthritis.’
    • ‘Biopsy specimens of those cysts and the liver cyst revealed benign mesothelial cysts and focal papillary mesothelioma.’
    • ‘At least a third of women with multiple miscarriages appear to have polycystic ovary syndrome, which is characterized by hormonal abnormalities and multiple cysts on the ovaries.’
    • ‘In rare cases, ovarian cysts can cause abnormal amounts of hormones to be produced.’
    • ‘Sometimes a thin needle is used to puncture the cyst and take out fluid to test for the Echinococcus infection.’
    growth, abscess, boil, blister, bleb, wen, carbuncle
    View synonyms
  • 3Zoology
    A tough protective capsule enclosing the larva of a parasitic worm or the resting stage of an organism.

    • ‘Potato cyst eelworms are normally hatched from their protective cyst in spring.’
    • ‘Some filters can remove even small organisms like cysts and bacteria and small particles like asbestos fibers.’
    • ‘The cysts contain tapeworm larvae that develop into adult worms in people who eat under-cooked or raw meat from an infested pig.’
    • ‘The internal structure of the organism contained within the cyst can be easily appreciated.’
    • ‘At least three minutes of boiling is necessary but 20 minutes of boiling will make water safe and pure from all the harmful bacteria viruses, worms and cysts of amoeba.’
    • ‘Giardia organisms form a resistant cyst that is shed by the host in its waste.’
    • ‘One gram of fecal matter can contain 10 million viruses, one million bacteria, 1,000 parasite cysts, and 100 worm eggs.’
    • ‘Resting cysts represent a dormant stage in which normal life processes are greatly reduced.’
    • ‘Vigorous boiling for one minute kills bacteria, including disease-causing organisms and giardia cysts.’
    • ‘The eggs mature to neotenous larvae inside the walls of the cyst.’


Early 18th century: from late Latin cystis, from Greek kustis ‘bladder’.