To lower in spirits
dispirit, dampen, dishearten, discourage, dismay, mortify, sadden, weary, darken, desolate, reduce to tears, deject, cow, weigh down, cast down, beat down, chill, dull, daunt, damp, oppress, prostrate, give an inferiority complex, cast gloom upon, cast a pall upon, make despondent, throw cold water on, put a damper on, bring down*, get down*, bum out*; see also discourage 1.
Antonyms encourage, animate, stimulate.