[ nem-uh-tuh-sist, ni-mat-uh- ]
/ ˈnɛm ə təˌsɪst, nɪˈmæt ə- /

noun Zoology.

an organ in coelenterates consisting of a minute capsule containing an ejectable thread that causes a sting.

Origin of nematocyst

First recorded in 1870–75; nemato- + -cyst
Related formsnem·a·to·cys·tic, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for nematocyst

British Dictionary definitions for nematocyst


/ (ˈnɛmətəˌsɪst, nɪˈmætə-) /


a structure in coelenterates, such as jellyfish, consisting of a capsule containing a hollow coiled thread that can be everted to sting or paralyse prey and enemies
Derived Formsnematocystic, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for nematocyst



1875, from nemato-, comb. form of Greek nema, nematos "thread" (genitive nematos), from stem of nein "to spin" (see needle (n.)) + cyst.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for nematocyst


[ nĕmə-tə-sĭst′, nə-mătə- ]


A capsule within specialized cells of certain coelenterates containing a barbed, threadlike tube that delivers a paralyzing sting.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for nematocyst


[ nĕmə-tə-sĭst′, nĭ-mătə-sĭst′ ]

One of the minute capsules in the tentacles of cnidarians, such as jellyfish, hydras, or sea anemones, used for stinging. The capsule is produced by a special cell (called a cnidoblast) and contains a tightly coiled barbed thread that quickly shoots forth if the capsule's lid is disturbed. The thread often contains poison.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.