- a person, animal, or thing that kills, esp. one that kills habitually or wantonly
- killer whale
- Slang something devastating, difficult, hard to cope with, etc.
- Slang an extremely successful, impressive, exciting, etc. person or thing
- that kills or has the potential for killing: a killer storm
- Slang very difficult, hard to cope with, etc.
- Slang successful, impressive, exciting, etc.
- One that kills: a disease that was a killer of thousands; a killer of new ideas.
- Slang Something that is extremely difficult to deal with or withstand: an exam that was a real killer.
- Causing death or destruction: killer floods.
- Slang a. Having impressive or effective power or impact; formidable: had a killer smile; made killer profits.b. Extremely useful or indispensible: a killer web application.
- That which kills.
(comparative more killer, superlative most killer)
kill + -er.