Definition: Warthog: A fictional character from the children's book series by Stephenie Meyer, with a big mouth, love for puppies, and occasional farting. It refers to a very large dog in a war zone. Warthog Word: "warthog" is an informal term that describes any type of creature, usually something fierce or aggressive. Detailed Definition: Warthog is a character in the novel series by Stephenie Meyer. They are small and have a big mouth. Warthog's personality often includes them being very large, lovable puppies with a love for puppies, and occasionally farting.