one who lies on impulse for no reason.

someone that repetitively lies over and over

An asshole who is always blowing shit out his mouth. And makes up stories to make himself look better, but winds up just driving himself further into the already huge hole in the ground.

Cum•pūl•sîvè | ly•îng | dîs•ōr•der

Compulsive Lying Disorder // the act of lying so frequently you start to believe your own lies

somone who lies all the time, for attention and to seem cool.
Often stories are to farfetched to be true.
When confronted about such lies they will often try to make the story more believeable.
Do you know one?

a term that someone will call someone else when they know they are wrong

A person that does not know how to tell the TRUTH