Definition of "killer" []

• One that kills: a disease that was a killer of thousands; a killer of new ideas. (noun)
• Slang Something that is extremely difficult to deal with or withstand: an exam that was a real killer. (noun)
• Causing death or destruction: killer floods. (adjective)
• Slang Having impressive or effective power or impact; formidable: had a killer smile; made killer profits. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Taking pain killer is pretty disastrous for his intestinal system and he mostly uses topical applications."
• "We are often told that the term killer whale is a misnomer, and that might be true in the wild as far as humans are concerned."
• "Doesn't she just give a whole new meaning to the term killer heels?"