A more thorough explanation:

Definition: Praevaricator (pree-var-uh-kay-tuhr) is another spelling of prevaricator (pri-var-uh-kay-tuhr), which means a person who lies or equivocates. In Roman law, it also refers to someone who betrays another's trust, such as a lawyer who helps the opposing party by betraying their client.

• John was caught in a prevaricator's trap when he believed the salesman's false promises.
• The lawyer was accused of being a praevaricator because he revealed his client's confidential information to the opposing party.

In the first example, John was deceived by a prevaricator who lied to him. In the second example, the lawyer was accused of being a praevaricator because he betrayed his client's trust by revealing confidential information to the opposing party. Both examples illustrate the definition of prevaricator/praevaricator as someone who lies or betrays trust.