Greenhouse/ˈɡriːnhaʊs/ Definition 1 of 2Pro Tip 1/3Cultivation Clarity Used for places where temperature and conditions are controlled to grow plants. The school installed a greenhouse to study tropical plants. Pro Tip 2/3Structure Type Often made of glass or clear plastic to let in sunlight for plants. You can see the rows of flowers through the greenhouse panels. Pro Tip 3/3Seasonal Use Emphasizes the ability to grow plants out of their typical season. They utilize the greenhouse to have fresh herbs all year round.