killer

killer

I

kill‧er¹ /ˈkɪlə $ -ər/ noun [countable]1. a person, animal, or thing that kills:
    Heart disease is America’s number one killer.
    the hunt for her killers
    weed killer ⇨ serial killer at serial²(1)
2. informal something or someone that is very difficult, tiring, or boring:
    The new project is a killer.
3. informal something that is very exciting or impressive:
    I’m not saying the film is a killer, but it’s cool.

II

killer² adjective [only before noun]1. very harmful or dangerous:
    a killer hurricane
    a swarm of killer bees
2. informal very attractive, good, impressive etc:
    a book called ‘How to Build a Killer Website’
3. killer instinct a very strong desire to succeed in a situation or activity etc that is very competitive:
    Young players these days lack the killer instinct.