adult

Universal Words noun, adjective noun 1 a fully grown person who is legally responsible for their actions: Children must be accompanied by an adult. * Why can't you two act like civilized adults? 2 a fully grown animal: The fish return to the river as adults in order to breed. adjective 1 fully grown or developed: preparing young people for adult life * the adult population * adult monkeys 2 behaving in an intelligent and responsible way; typical of what is expected of an adult: When my parents split up, it was all very adult and open. 3 [onlybeforenoun] intended for adults only, because it is about sex or contains violence: an adult movie seealsoADULTHOOD