Adult

Adult is originally a biological term that refers to a state of being attained maturity, which comes after completion of the period of adolescence. An adult is thus a biologically matured individual.
The term is applied not only for human beings but also for animals, birds, and most of the other life forms, typically multiplying through a process of reproduction. In this context, an adult is considered to be a sexually mature individual.
As a legal term, it refers to a person who has crossed the age of adolescence (minority) usually below the age of 18 yrs, and has attained majority (usually the age of 18 yrs and above). However, an adult is defined variously in legislations of the world keeping in view the various purposes like universal franchise, marriage, child labour, abduction etc, which ranges from 14 yrs to 21 yrs and differs for males and females.
Something related to, of, and for adult persons are also known as adult. It can be a toy, a movie, a book, a theme, an emotion, a behaviour and so on. The various laws for regulating such things also found defining the word ‘adult’, which greatly differs from country to country, and society to society.
Entertainment industry all over the world has its own laws defining the word ‘adult’, which essentially differ from each other.