This is the 12813th most frequent Portuguese word.
veterinário
Veterinário (Portuguese): Veterinarian; a doctor who treats animals.
Here, 'veterinário' is a noun, referring to a professional who provides medical care to animals.
O veterinário cuidou muito bem do meu cachorro doente.
The veterinarian took very good care of my sick dog.
In this case, 'veterinária' is used to indicate the profession someone is aiming for, with a gender agreement as the ending is feminine due to the subject being female.
Ela está estudando para ser uma veterinária.
She is studying to become a veterinarian.
Here, 'veterinário' is used as an adjective to describe the type of clinic, specifically one dealing with animal health.