“Welkin” comes from the Old English “wolcen,” meaning “cloud, sky,” but the word is also rooted in the West Germanic languages: It’s related to the Dutch “wolk” and German “Wolke.” In contemporary use, you may hear “welkin” incorporated into ecclesiastical phrases, such as “make the welkin ring” (which means to make loud, reverberating noise). This usage calls back to the original wording of the 1739 English Christmas carol “Hark! The Herald Angels Sing,” which used to read, “Hark, How All the Welkin Rings.”