demoralize
verb [ T ] (UK usually demoralise) uk/dɪˈmɒr.ə.laɪz/ us/dɪˈmɔːr.ə.laɪz/
使泄气，使垂头丧气
to make someone or something feel much less confident
Losing several games in a row had completely demoralized the team. 连续输掉数场比赛使全队上下彻底泄了气。