noun, plural sto·ma·ta [stoh-muh-tuh, stom-uh-, stoh-mah-tuh] /ˈstoʊ mə tə, ˈstɒm ə-, stoʊˈmɑ tə/, sto·mas.

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 formssto·mal, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for stoma

orifice, opening, vesicle, outlet, foramen, halo

Examples from the Web for stoma

Historical Examples of stoma

  • 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 plural 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 ileumSee colostomy, ileostomy

Word Origin for stoma

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

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

stoma in Medicine



n. pl. sto•mas

A minute opening or pore, as in the surface of a membrane.
A mouthlike opening, such as the oral cavity of a nematode.
A surgically constructed opening, especially one made in the abdominal wall to permit the passage of waste.
Related formsstomal adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

stoma in Science



Plural stomata (stōmə-tə)

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.
Zoology A mouthlike opening, such as the oral cavity of a nematode.
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 © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.