A slayer is someone who kills something, especially something dangerous or evil. The word appears most often in fantasy stories and video games, where heroes become dragon slayers, vampire slayers, or demon slayers by defeating these threatening creatures. In the classic tale of Saint George and the Dragon, Saint George becomes a dragon slayer when he saves a village from a terrorizing beast.

While “kill” is the everyday word we use, “slay” and “slayer” carry a more dramatic, heroic feeling. You wouldn't call someone an “ant slayer” for stepping on an ant, but you might jokingly call your friend a “spider slayer” after they bravely moved a huge spider out of the classroom.

In modern usage, people sometimes use slayer more playfully to mean someone who's exceptionally good at something difficult. A student who aces an extremely hard math competition might be called a “math slayer.” But whether used seriously in fantasy literature or playfully in everyday conversation, slayer suggests skill, courage, and triumph over something challenging or fearsome.