downer/ˈdaunə(r); `daʊnɚ/ n(sl 俚)1 drug having a depressant effect, esp a barbiturate 抑制药, 镇静药（尤指巴比妥类）. Cf 参看 upper n 2.2 depressing experience, person, etc 令人沮丧的经历、 人等 What a downer that guy is! 那家伙多让人泄气呀!
牛津英汉双解词典