Slayer is a striking word that refers to a person who kills another person or animal in a brutal manner. But in the realm of synonymy, several words can be used in place of slayer to convey comparable meanings. For instance, assassin is another term for a professional killer. Likewise, executioner refers to someone who carries out death sentences. Meanwhile, the word hunter suggests someone who pursues and kills animals for sport or livelihood. Other words with related meanings include killer, murderer, exterminator, and terminator. All in all, while the term slayer can bring to mind brutal and violent acts of killing, there are many other words you can use to describe someone who takes the life of another.