When he lies, he speaks out of his own character, for he is a liar and the father of lies.  (John 8:44b)

Jesus is speaking of the devil, who is elsewhere in the Bible shown to be Satan and he is the original deceiver.

The Greek word translated ‘lie’ is the verb ψεύδομαι (pseudomai) and it means ‘to falsify’ or ‘to wilfully misrepresent’.