- an action or instance of transpiring.
- Botany. the passage of water through a plant from the roots through the vascular system to the atmosphere.
Origin of transpiration
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for transpiration
The greatest factor, however, is transpiration of water from leaves.
Evaporation of water from green leaf, regulation of transpiration.
Why, madam, a blow like this would set a frog into a transpiration.The Works of Robert Louis Stevenson
Robert Louis Stevenson
His book begins with the research for which he is best known, namely that on transpiration.
With the cutting off of the water supply at the roots in late fall, transpiration is also cut off.Trees Worth Knowing
Julia Ellen Rogers
Word Origin and History for transpiration
early 15c., from Medieval Latin transpirationem, noun of action from transpirare (see transpire).
Online Etymology Dictionary, © 2010 Douglas Harper
- The passage of watery vapor through the skin or through any membrane or pore.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- The process of giving off vapor containing water and waste products, especially through the stomata on leaves or the pores of the skin.
A Closer Look: Plants need much more water than animals do. But why? Plants use water not only to carry nutrients throughout their tissues, but also to exchange gases with the air in the process known as transpiration. Air, which contains the carbon dioxide that plant cells need for photosynthesis, enters the plant mainly through the stomata (tiny holes under its leaves). The air travels through tiny spaces in the leaf tissue to the cells that conduct photosynthesis. These cells are coated with a thin layer of water. The cell walls do not permit gases to pass through them, but the carbon dioxide can move across the cell walls by dissolving in the water on their surface. The cells remove the carbon dioxide from the water and use the same water to carry out oxygen, the main waste product of photosynthesis. All this mixing of water and air in transpiration, though, has one drawback: more than 90 percent of the water that a plant's roots suck up is lost by evaporation through the stomata. This is why a plant always needs water and why plants that live in dry climates, such as cacti, have reduced leaf surfaces from which less water can escape.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.