Kill"er (?), n. 1. One who deprives of life; one who, or that which, kills.

2. (Zoöl.) A voracious, toothed whale of the genus Orca, of which several species are known.

&fist; The killers have a high dorsal fin, and powerful jaws armed with large, sharp teeth. They capture, and swallow entire, large numbers of seals, porpoises, and dolphins, and are celebrated for their savage, combined attacks upon the right whales, which they are said to mutilate and kill. The common Atlantic species (Orca gladiator), is found both on the European and the American coast. Two species (Orca ater and O. rectipinna) occur on the Pacific coast.

• A person who kills.
  
• A murderer.
  
• An animal that kills.
  
• Something that causes death.
       Driving while tired can be a killer.
  
• A diacritic mark used in Indic scripts to suppress an inherent vowel.
  
• Also used attributively.