מֵם דָּלֶת
memdalet
Everyday HebrewMeaningSomething or someone that spoils a good mood or a fun time.
HistoryThis is a modern Israeli slang phrase. It is made from the first letters of the words "מוריד דיכאון" (morid dika'on), which means "brings down sadness". But people use it in a funny, opposite way to mean something that causes sadness or kills a good mood.
Example
Don't be a buzzkill, the party just started.