What do you call the process by which plants lose water vapor to the atmosphere?

Transpiration is the correct term for the process by which plants lose water vapor to the atmosphere. This process primarily occurs through small openings in the leaves called stomata. As plants absorb water from the soil for photosynthesis and nutrient transport, they inevitably lose some of this water to the atmosphere through transpiration. This mechanism helps maintain the plant's internal temperature and facilitates the uptake of more water and nutrients from the roots.

While evaporation refers more generally to the process of a liquid turning into vapor, it does not specifically involve plants or their biological functions. Condensation, on the other hand, is the process of water vapor cooling and forming liquid water, which is the opposite of what occurs during transpiration. Photosynthesis is the process by which plants convert sunlight into energy, involving the absorption of carbon dioxide and water, but doesn't specifically address the loss of water vapor. Therefore, transpiration is the most accurate term for the process described.