A person telling fibs is commonly referred to as a LIAR. The term 'LIAR' is a four-letter word that is used to describe someone who is not telling the truth. A LIAR is someone who deliberately misleads or deceives others by making false statements. They may also omit important information or distort facts in order to gain an advantage or avoid responsibility. Liars often use their lies to manipulate or control others, and they may even believe their own lies.