Medieval slang term for the the English
longbow, referring to the fact that it was really effective in
getting rid of those pesky knights in their
full body armor.
From the point of view of a longbow arrow, chainmail can be thought of as a series of loosely connected holes.
-- Terry Pratchett, don't remember which book. Lords and Ladies, perhaps?
Ok, so much for the joke on a misspelling of Knight Rider that most people will see here, but Knight Ridder is actually the name of a large publishing company that owns a lot of local newspapers in the USA. They are listed on the New York Stock Exchange as KRI.