Definition from Wiktionary, the free dictionary
greenhouse (plural greenhouses)
- A building traditionally made of glass, but now also made from plastics such as polyethylene, in which plants are grown more rapidly than outside such a building by the action of heat from the sun, this heat being trapped inside by the glass or plastic.
Usage notes 
- In the UK, greenhouse is the term used domestically. Large commercial greenhouses are called glasshouses by professionals.
- glasshouse (chiefly commercial)
Derived terms 
building in which plants are grown more quickly than outside
See also 
From English greenhouse.
greenhouse f (plural greenhouses)