knife1 S3 W3 plural knives [countable]
a metal blade fixed into a handle, used for cutting or as a weapon [↪ scalpel]:
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.
used to say that people are being extremely unfriendly in criticizing someone:
The knives are out for the vice president.
to say something that makes someone more upset about a subject they are already unhappy about
4 British English informal
to dislike someone and be very unfriendly towards them
having a medical operation
used to say that you felt the people in a room were angry with each other
used to say that something happens or is done very easily, without any problems