Definition of "cyst" [cyst]

• Pathology An abnormal membranous sac containing a gaseous, liquid, or semisolid substance. (noun)
• Anatomy A sac or vesicle in the body. (noun)
• Biology A small capsulelike sac that encloses certain organisms in their dormant or larval stage. (noun)
• Botany A thick-walled resting spore, as in certain algae or fungi. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Assuming the cyst is a warning sign that he will soon meet his maker, he is determined to do two things before he dies; he needs to regain what he believes he let slide; his ties to his wife and his estranged grandson Daniel, an Alaskan fisherman running away from home since his parents died years ago."
• "And there's another stage, which we call the cyst phase, where they go to sleep."
• "Pull your head out of your ass, the anal cyst is cutting off the flow of blood to your brain."