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[stoh-muh] /ˈstoʊ mə/
noun, plural stomata
[stoh-muh-tuh, stom-uh-, stoh-mah-tuh] /ˈstoʊ mə tə, ˈstɒm ə-, stoʊˈmɑ tə/ (Show IPA),
Also, stomate. Botany. any of various small apertures, especially one of the minute orifices or slits in the epidermis of leaves, stems, etc., through which gases are exchanged.
Zoology. a mouth or ingestive opening, especially when in the form of a small or simple aperture.
Medicine/Medical. an artificial opening between two hollow organs or between one hollow organ and the outside of the body, constructed to permit the passage of body fluids or waste products.
Origin of stoma
1675-85; < New Latin < Greek stóma mouth
Related forms
stomal, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for stoma
Historical Examples
  • stomate (Latin stoma, plural stomata), the breathing-pores of leaves, 144.

  • By change in shape of these cells the opening of the stoma is made larger or smaller.

    A Civic Biology George William Hunter
  • Poson oun estin, ho alloioi, kai d theasmetha; pleon men kata to stoma, meion d' kata to Pg 252Greek text hpar te kai tas phlebas.

British Dictionary definitions for stoma


noun (pl) stomata (ˈstəʊmətə; ˈstɒm-; stəʊˈmɑːtə)
(botany) an epidermal pore, present in large numbers in plant leaves, that controls the passage of gases into and out of a plant
(zoology, anatomy) a mouth or mouthlike part
(surgery) an artificial opening made in a tubular organ, esp the colon or ileum See colostomy, ileostomy
Word Origin
C17: via New Latin from Greek: mouth
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
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Word Origin and History for stoma

"orifice, small opening in an animal body," 1680s, Modern Latin, from Greek stoma (genitive stomatos) "mouth," from PIE root *stom-en-, denoting various body parts and orifices (cf. Avestan staman- "mouth" (of a dog), Hittite shtamar "mouth," Middle Breton staffn "mouth, jawbone," Cornish stefenic "palate"). Surgical sense is attested from 1937.

Online Etymology Dictionary, © 2010 Douglas Harper
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stoma in Medicine

stoma sto·ma (stō'mə)
n. pl. sto·mas or sto·ma·ta (-mə-tə)

  1. A minute opening or pore, as in the surface of a membrane.

  2. A mouthlike opening, such as the oral cavity of a nematode.

  3. A surgically constructed opening, especially one made in the abdominal wall to permit the passage of waste.

sto'mal adj.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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stoma in Science
Plural stomata (stō'mə-tə)
  1. Botany One of the tiny openings in the epidermis of a plant, through which gases and water vapor pass. Stomata permit the absorption of carbon dioxide necessary for photosynthesis from the air, as well as the removal of excess oxygen. Stomata occur on all living plant parts that have contact with the air; they are especially abundant on leaves. A single leaf may have many thousands of stomata. Each stoma is generally between 10 to 30 microns in length and is surrounded by a pair of crescent-shaped cells, called guard cells. The guard cells can change shape and close the stoma in order to prevent the loss of water vapor. See Note at transpiration.

  2. Zoology A mouthlike opening, such as the oral cavity of a nematode.

  3. Medicine A temporary or permanent opening in a body surface, especially the abdomen or throat, that is created by a surgical procedure, such as a colostomy or tracheostomy.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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