noun
operation, surgery
B1
Operation (die) means 'operation' or 'surgery' — can refer to a medical procedure, a military or technical action, or a general operation/process. Plural: Operationen. No special preposition. Regular feminine noun. Use context to decide meaning: in hospitals it means 'surgery', in business/technology it denotes a procedure or operation.
Examples
Die Operation war erfolgreich.
The operation was successful.
Nach der Operation braucht er viel Ruhe.
He needs a lot of rest after the surgery.
Der Arzt erläuterte die Risiken der Operation, bevor der Patient eine Entscheidung traf.
The doctor explained the risks of the operation before the patient made a decision.
Details
Mnemonics
Imagine a hospital operating room with a sign that says 'Operation' above the door.
Sounds like 'operation' in English—think 'operation room'.
Die Operation — think of 'die' as 'the' for events that happen to a person (surgery), often feminine words ending in -ion are 'die'.
Notes
In German, 'Operation' most commonly refers to a surgical procedure but can also mean other kinds of operations (e.g., military or technical). The plural is 'Operationen'. Many German nouns ending in -ion are feminine.