Knife

knife1 S3 W3 plural knives [countable]

1DDFU a metal blade fixed into a handle, used for cutting or as a weapon

a knife and fork

Some young people are carrying knives to defend themselves.

a kitchen knife

Use a sharp knife to cut the melon into sections.

2 the knives are out (for somebody) informal used to say that people are being extremely unfriendly in criticizing someone:

The knives are out for the vice president.

3 twist/turn the knife (in the wound) to say something that makes someone more upset about a subject they are already unhappy about

4 stick/put etc the knife in/into someone British English informal to dislike someone and be very unfriendly towards them

5 under the knife informal having a medical operation

6 you could cut the atmosphere/air/tension with a knife used to say that you felt the people in a room were angry with each other

7 like a (hot) knife through butter informal used to say that something happens or is done very easily, without any problems