A veterinarian is an animal doctor — someone who studied medicine for animals at university and is licensed to examine them, work out what is wrong, give medicine, do operations, give vaccinations, and, when an animal is suffering with no hope, end its life gently. Most people meet one because of a pet: a dog, a cat, a rabbit, a bird. But veterinarians also work with farm animals, horses, zoo animals, and wild animals, and some work in laboratories or for the government checking that meat and animal diseases are under control. The big thing to know is which word people actually say. In everyday speech almost nobody says the full four-syllable veterinarian — they say vet. 'I'm taking the cat to the vet.' The long word appears on a clinic sign, on a name card, in a job advertisement, in a news report, or when someone is being formal or proud about the profession. The other big thing is that veterinarian is the American word. British, Australian, and New Zealand speakers say vet in speech too, but when they need the full form they usually write 'veterinary surgeon' or just 'veterinary', and veterinarian sounds American to their ear. In Taiwan, textbooks and school exams tend to teach veterinarian, so students often produce the long word in conversation and sound a little stiff. One more useful point: in American English vet has a second, completely separate meaning — a veteran, someone who served in the army. Context nearly always makes it clear, but that is why an American writer will sometimes choose the long word on purpose.