Pronunciation: (i-val'yOO-āt"),[key] —v.t.,-at•ed, -at•ing. 1. to determine or set the value or amount of; appraise: to evaluate property. 2. to judge or determine the significance, worth, or quality of; assess: to evaluate the results of an experiment. 3. Math.to ascertain the numerical value of (a function, relation, etc.).