1. kill file - Noun
2. kill file - Verb
English Wikipedia has an article on:kill fileWikipedia
kill file (plural kill files)
(Internet) A user's file listing the users of a newsgroup whose postings are to be ignored, or other criteria for ignoring posts.
Synonyms: (slang) bozo filter, bozo bin
kill file (third-person singular simple present kill files, present participle kill filing, simple past and past participle kill filed)
(Internet) To add (a user) to a kill file.