Kill-joys are people who spoil the fun by being overly critical or negative. There are a variety of synonyms that can be used to describe these types of individuals. Some common ones include party pooper, wet blanket, buzzkill, spoilsport, and stick-in-the-mud. Other options might include buzzard, killjoy, dampener, crank, or spoilsport. The key thing to remember is that these words all describe someone who takes the enjoyment out of a situation or event. Whether it's a friend who constantly complains about the music at a party or a coworker who always shoots down ideas during a brainstorming session, a kill-joy is never a welcome addition to any gathering.