The term also exists, albeit with a different meaning, in the roleplaying system "Vampire: The Masquerade" and various spin-offs. It signifies the "offspring" of a vampire, in this respect called a "Sire".
Childe in Stephen King's The Dark Tower (series) is, in Roland Deschain's own words, "...a term that describes a knight - or a gunslinger - on a quest. A formal term, and ancient. We never used it among ourselves...for it means holy, chosen by ka. We never liked to think of ourselves in such terms, and I haven't thought of myself so in many years." (p. 859, The Dark Tower VII: The Dark Tower, Pocket Books, 2006 ed.)