down·er
noun/ˈdaʊnə(r)/
/ˈdaʊnər/
(informal)- [usually plural] a drug, especially a barbiturate, that relaxes you or makes you want to sleep
镇静药，抑制药（尤指巴比妥类） - an experience that makes you feel sad or depressed
令人悲哀（或沮丧）的经历 - Not getting the promotion was a real downer.
未得到提升真让人很沮丧。 - on a downer He's really on a downer (= very depressed).
他确实很郁闷。
- Not getting the promotion was a real downer.