Green’s Dictionary of Slang

(teen) an act/statement of rejection.

[1978		R. Charles Brother Ray 120: When I cancel a person, that’s it. They become grains of sand; I just don’t pay them any mind].
2019		www.verywellfamily.com/a-teen-slang-dictionary 10 Mar. 🌐 Cancel - A rejection of a person, place or thing.