To be more specific, what is transpiration in plants?
The special reference to plants should be proper and is not without basis. It is because this process is not exclusive to plants.
It also occurs in mushrooms.
This paper and its component pages relate to the kingdom Plantae.
The word is the noun ‘transpire‘ from Latin trans, meaning across or through, and spirare or breathe.
It is the natural process by which liquid water within the plant is converted to gas and, in this state of matter, lost via various aerial organs but primarily through the leaves.
Stated simply, it is the evaporation of water from plants.
Stephen Hales (1677-1761) referred to it as perspiration.