der Teller
plate
A flat or slightly hollow dish from which food is eaten.
Nach dem Essen stelle bitte deinen Teller in die Spülmaschine.
After eating, please put your plate in the dishwasher.

plate
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plate
A flat or slightly hollow dish from which food is eaten.
Nach dem Essen stelle bitte deinen Teller in die Spülmaschine.
After eating, please put your plate in the dishwasher.

The verb in the sentence reveals the meaning: verbs like 'abwaschen' (to wash up) or 'decken' (to set the table) refer to the dishware. Verbs like 'essen' (to eat) or 'aufessen' (to finish eating) refer to the meal on it.
Kannst du bitte die sauberen Teller in den Schrank stellen?
Can you please put the clean plates in the cupboard?
The idiom 'über den Tellerrand schauen' literally means to look beyond the edge of one's plate. It means to be open to new things and to look beyond one's own horizon. It is used very frequently.
Wer eine neue Sprache lernt, schaut automatisch über den eigenen Tellerrand.
Anyone who learns a new language automatically looks beyond their own horizon.
In everyday life, people often distinguish between a 'flacher Teller' (flat plate) for main courses and a 'tiefer Teller' (deep plate/bowl) for soups or stews.
Für die Suppe brauchst du einen tiefen Teller.
You need a deep plate for the soup.
When 'Teller' (plate) describes a portion, the dish often follows directly, e.g. 'ein Teller Nudeln' (a plate of noodles) or 'ein Teller Salat' (a plate of salad).
Zum Mittagessen gab es einen großen Teller Gemüse.
For lunch, there was a large plate of vegetables.
This meaning occurs only in technical contexts. It often describes a round, flat disk in a device, for example the 'Plattenteller' (turntable platter) in a record player.
Beim Ventilmotor schließt der Ventilteller die Öffnung.
In a valve engine, the valve plate closes the opening.
dish / court
'das Gericht' and 'der Teller' can both appear in the context of eating, but they do not mean the same thing. 'Gericht' means the prepared dish, for example soup, pasta, or vegetables with rice. 'Teller' usually means the dishware you eat from. Sometimes 'Teller' can also mean a portion of food, for example 'einen Teller Suppe' (a bowl/plate of soup). Learners may confuse the words because food is often served on a plate. Remember: the 'Gericht' is the food itself; the 'Teller' is normally the dish or the portion on it.

Nach dem Essen stellt Paul seinen Teller in die Küche.
After eating, Paul puts his plate in the kitchen.
Das vegetarische Gericht mit Linsen schmeckt heute besonders gut.
The vegetarian dish with lentils tastes especially good today.