A warthog is a wild pig that lives in Africa, mostly on open grassland. It is grey, nearly hairless except for a rough mane along its back, and it has two pairs of tusks — long curved teeth that stick out sideways from its mouth. Its face has thick lumps of skin on it, and those lumps are what gave the animal its name: people thought they looked like warts, the small hard bumps that can grow on human skin.

Warthogs eat grass and roots. When they eat they often go down on their front knees, which is a strange sight, and when they run away they hold their thin tails straight up in the air like little flags. They sleep in holes in the ground that other animals dug. They are not usually dangerous to people but they will fight with their tusks if cornered.

Most Taiwanese students first meet this animal not in a zoo but in *The Lion King* — Pumbaa is a warthog. If you are ever stuck for the meaning, that picture is a good one to hold onto.

It is countable: one warthog, a group of warthogs. Nothing tricky about it grammatically; it is simply the name of an animal, useful for nature programmes, zoos, and safari talk.