A heron is a large water bird with long thin legs, a long neck, and a long sharp beak. It stands very still in shallow water, then strikes fast to catch fish. You see herons by rivers, lakes, wetlands, and rice fields. The grey heron is the one English learners usually mean; there are other kinds too, some smaller, some with different colours. It is a plain nature word — not slang, not fancy. Though actually, people mix up herons and egrets. Egrets are close relatives, often whiter, and in Chinese they can share the same family of names. If you see a tall grey bird waiting in a ditch as if it had all day, heron is the English word you want.