fail to meet the hopes or expectations of; " Her boyfriend let her down when he did not propose marriage"

To defeat of expectation or hope; to hinder from the attainment of that which was expected, hoped, or desired; to balk; as, a man is disappointed of his hopes or expectations, or his hopes, desires, intentions, expectations, or plans are disappointed; a bad season disappoints the farmer of his crops; a defeat disappoints an enemy of his spoil.

To frustrate; to fail; to hinder of result.

To fall to gratify; to defeat of hope; frustrate; fail to keep an appointment with.

Disappointed.

To deprive one of what he expected: to frustrate.

To frustrate ( a hope or plan).

To defeat what is expected or intended; to fail to gratify one's wish; to frustrate; to balk.

To defeat expectation; to frustrate; to foil; to balk; to hinder from possession or enjoyment.

I hope 'twon't disappoint you! – Max by Katherine Cecil Thurston

I never knew a red- headed gal to disappoint a fellow yet." – The Comings of Cousin Ann by Emma Speed Sampson

I dared not disappoint him by telling him that I loved Charley Osborne. – Wilfrid Cumbermede by George MacDonald

Lisette was to have accompanied them, but she was suffering from a headache, and, rather than disappoint the girls, Mrs. Farrington said that just for this once they might go shopping alone in the motor- car with the chauffeur. – Patty in Paris by Carolyn Wells

Even now he need not disappoint his mother. – The Higher Court by Mary Stewart Daggett

Curiously enough the news, instead of pleasing, seemed to disappoint him. – The Lost Valley by J. M. Walsh

Rob always did as I told him, and he will not disappoint me now. – More About Peggy by Mrs G. de Horne Vaizey

I do not think that he will disappoint you. – A People's Man by E. Phillips Oppenheim

He knew Howard, who, after Jack was through, said he hoped Mr. Bills would wait; it would be a pity to disappoint the girl when she had come so far. – The Cromptons by Mary J. Holmes

I can't disappoint any one. – The Great Impersonation by E. Phillips Oppenheim

It is my task to disappoint his mistress, as he terms her, though it must be confessed that she does not sleep at her post." – The Water-Witch or, The Skimmer of the Seas by James Fenimore Cooper

Do not disappoint me. – A Little Girl in Old Philadelphia by Amanda Minnie Douglas

For heaven's sake, don't disappoint us all! – The Great Impersonation by E. Phillips Oppenheim

If free in the full sense of the word, they would not disappoint this expectation. – Complete State of the Union Addresses from 1790 to the Present by Various