The
term
adult
describes
any
mature
organism,
but
normally
it
refers
to
a
human:
one
that
is
no
longer
a
child
and
is
now
either
a
man
or
a
woman.
When
someone
becomes
an
adult,
they
enter
adulthood.
For
humans,
the
legal
definition
of
entering
adulthood
varies
between
ages
17-21,
depending
on
the
region
in
question.
Some
cultures
in
Africa
define
adult
at
age
13,
but
most
other
civilizations
consider
this
the
teenager
stage.