From Longman Dictionary of Contemporary Englishdash somebody’s hopesdash somebody’s hopesDISAPPOINTEDto disappoint someone by telling them that what they want is not possible Hopkins’ hopes were dashed when his appeal was denied. → dash
Examples from the Corpus
dash somebody’s hopes• a shattering knee injury which dashed his hopes of playing in the World Cup• I didn't want to dash your hopes unnecessarily. 