Dishearten, v. t. [imp. & p. p. Disheartened; p. pr. & vb. n. Disheartening.]
Etymology: [Pref. dis- + hearten.]
To discourage; to deprive of courage and hope; to depress the spirits of; to deject. Regiments . . . utterly disorganized and disheartened. Macaulay.
Syn. -- To dispirit; discourage; depress; deject; deter; terrify.
Shades of meaning
Fernald has no entry of its own for dishearten; he lists it under abash.
He lists it without comment; the entries above explain its neighbors.