Adult means relating to the time when you are an adult, or typical of adult people.
I've lived most of my adult life in Arizona.
我已在亚利桑那州度过了我大部分的成年生活。
You can describe things such as films or books as adult when they deal with sex in a very clear and open way.
an adult movie.
一部成人电影。
adults
An adult is a mature, fully developed person. An adult has reached the age when they are legally responsible for their actions.
Becoming a father signified that he was now an adult.
成为一名父亲意味着他现在是一个成年人了。
The course is suitable for teenagers and young adults.
这门课程适合青少年和年轻人。
An adult is a fully developed animal.
a pair of adult birds.
一对成鸟。