If you slash something, you make a long, deep cut in it.

If you slash at a person or thing, you quickly hit at them with something such as a knife.

To slash something such as costs or jobs means to reduce them by a large amount.

You say slash to refer to a sloping line that separates letters, words, or numbers. For example, if you are giving the number 340/2/K you say 'Three four zero, slash two, slash K.'