The Collaborative International Dictionary of English v.0.48:

Parol \Pa*rol"\, a.
   Given or done by word of mouth; oral; also, given by a
   writing not under seal; as, parol evidence.
   [1913 Webster]

   Parol arrest (Law), an arrest in pursuance of a verbal
      order from a magistrate.

   Parol contract (Law), any contract not of record or under
      seal, whether oral or written; a simple contract.
      --Chitty. Story.
      [1913 Webster]