transpiration

/ˌtrænspəˈreɪʃən/

Other forms: transpirations

Plants breathe through their stomata, little openings that allow transpiration, which is the outward passage of water vapor along with carbon dioxide. This vapor then evaporates into the air as part of the process of photosynthesis.

We can see the history of the word transpiration when we break it down into trans, a Latin noun which means "across," and spiration, which comes from the Latin verb spīrāre, meaning "to breathe." The tion suffix adds the meaning "the act of," so we can see transpiration is, literally, "the act of breathing across," which clearly identifies vapor emission from plant leaves. Transpiration is vital to the earth’s ecology, and is being reduced by our decimation of the forests.

Definitions of transpiration

1. noun

   the emission of water vapor from the leaves of plants
   type of:

   biological process, organic process

   a process occurring in living organisms
2. noun

   the process of giving off or exhaling water vapor through the skin or mucous membranes
   type of:

   activity, bodily function, bodily process, body process

   an organic process that takes place in the body
3. noun

   the passage of gases through fine tubes because of differences in pressure or temperature
   type of:

   action, activity, natural action, natural process

   a process existing in or produced by nature (rather than by the intent of human beings)