A mostly glass room attached to a house where plants can overwinter or that is used as a bright living space. It makes it possible to sit 'im Grünen' (surrounded by greenery) even in cool weather.
example
Wir trinken unseren Nachmittagskaffee am liebsten im Wintergarten.
We like to drink our afternoon coffee in the sunroom.
Usage tips
Word composition
The word is made up of 'der Winter' (winter) and 'der Garten' (garden). The logic behind it is that it refers to a garden-like room that can also be used in winter.
EXAMPLE
Im Wintergarten ist es auch bei Schnee schön hell.
In the sunroom, it is beautifully bright even when there is snow.
False friend
Careful: the German 'Wintergarten' (sunroom/conservatory) is usually a private glass room attached to a house. The English 'winter garden' often refers to a public park or a theater, which have other names in German.
EXAMPLE
Unsere Nachbarn haben sich einen Wintergarten an ihr Haus anbauen lassen.
Our neighbors had a sunroom added to their house.
Correct preposition
To indicate a location, you use 'im Wintergarten' (in the sunroom; dative). To express movement toward it, you say 'in den Wintergarten' (into the sunroom; accusative).
EXAMPLE
Die Katze schläft gerne in der Sonne im Wintergarten.
The cat likes to sleep in the sun in the sunroom.
Compare with
confusable
Wintergarten vs Terrasse
terrace / patio
'die Terrasse' and 'der Wintergarten' both often belong to a house and are places where you can sit close to the garden. The difference is important: a 'Terrasse' (terrace / patio) is an open area outside, usually directly next to the house. A 'Wintergarten' (sunroom / conservatory) is an attached room with lots of glass and a roof. You can sit there protected from the weather, even when it is cool or raining. Learners may confuse the words because both are used as bright places to sit. If you are really outdoors, you say 'Terrasse'. If it is an enclosed glass room, you say 'Wintergarten'.
Wintergarten
Bei Regen sitzen die Gäste im Wintergarten und schauen in den Garten.
When it rains, the guests sit in the sunroom and look out into the garden.
Terrasse
Am Abend essen wir auf der Terrasse, weil es noch warm ist.
In the evening, we eat on the terrace because it is still warm.