The Collaborative International Dictionary of English v.0.48:
overappraisal \overappraisal\ n. an appraisal that is too high. Syn: overestimate, overestimation, overvaluation. [WordNet 1.5]WordNet (r) 3.0 (2006):
overappraisal n 1: an appraisal that is too high [syn: overestimate, overestimation, overvaluation, overappraisal]