A complete agreement is a consensus between two or more parties, where all parties are in agreement. The term 'complete agreement' can be expressed in three different ways: UNISON (6 letters), UNANIMITY (9 letters), and UNANIMOUS (9 letters). UNISON is derived from the Latin word 'unio' which means 'UNITY'. UNANIMITY is derived from the Latin word 'unanimus' which means 'of one mind'. UNANIMOUS is derived from the Latin word 'unanimis' which means 'all of one mind'. All three terms refer to a situation where all parties involved are in agreement.