To fail to satisfy the hope, desire, or expectation of.
To frustrate or thwart: "I will not disappoint the confidence you have put in me” ( Wayne A. Budd).
To cause disappointment.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.