What is the test for upholding an agreement where the terms of the agreement are not clearly defined?

There is no doubt that it is desirable to uphold an agreement where one is reached. In order for an agreement to be reached there must be a clear meeting of the minds on the terms of the agreement. If the parties fail to reach a meeting of the minds on the essential terms of their agreement or fail to express themselves in such a fashion that the meaning of the terms they agreed upon cannot be reasonably defined by the court, then the agreement will fail for lack of certainty (Frolick v. Frolick, 2007 BCSC 84).