A child is a young person that is not an adult yet. Parents often refer to their sons and daughters as children even after they become adults.
Something is wild if people haven't changed it to suit their own needs. Wild animals and plants live or grow anywhere they are able, and don't rely on people to feed them and look after them. The opposite of wild is domesticated. Wild versions of household flowers, fruits and vegetables generally have much smaller fruits or flowers than their domestic varieties.