dis ‧ heart ‧ ened /dɪsˈhɑːtnd $ -ɑːrtnd/ BrE AmE adjective formal
[ Word Family: adjective : heartened ≠ ↑ disheartened , ↑ heartening ≠ ↑ disheartening , ↑ heartless , ↑ hearty ; noun : ↑ heart , ↑ heartlessness , ↑ heartiness ; adverb : ↑ heartily , ↑ heartlessly , ↑ hearteningly ≠ ↑ dishearteningly ; verb : ↑ hearten ≠ ↑ dishearten ]
disappointed, so that you lose hope and the determination to continue doing something:
If young children don’t see quick results they grow disheartened.
—dishearten verb [transitive]