Something that's wild lives in nature and isn't tamed. Your pet poodle isn't wild, but the groundhog that lives under your garden shed is wild.
An animal or plant in its native habitat is wild, like a wild dingo or a wild strawberry. An untamed bit of nature, like your overgrown back yard, or a stormy ocean, is also wild. If a person is wild, he might be unrestrained, crazy, or even enthusiastic — like someone who's wild about cabaret music. The term "to run wild" means to grow unrestrained, undisciplined, like a wild animal or an imagination that isn't held back by rules.