killer

Noun

• predatory black-and-white toothed whale with large dorsal fin; common in cold seas

• a difficulty that is hard to deal with
  • that exam was a real killer
    

• the causal agent resulting in death
  • heart disease is the biggest killer in the United States
    

• someone who causes the death of a person or animal

Related words

• Synonyms: 
  killer whale , orca , grampus , sea wolf , Orcinus orca , cause of death , slayer