is used in a variety of contexts mainly when
it is referring to someone you think
of as a friend, as a greeting and as a way of saying thank
you. The word
is derived from the idea of literally being 'safe' when
you are with a person, the idea that you will
come to no harm.
He is safe, do not hit him.
Safe for letting
me borrow your pencil.
Safe, I will speak to you tomorow.