Yours, Etc.: Origins and Uses of 8 Sign-Offs
"medicinal or mineral spring," 1620s, from name of health resort in eastern Belgium, known since 14c., that featured mineral springs believed to have curative properties. The place name is from Walloon espa "spring, fountain."
municipality, Walloon Region, eastern Belgium. It is situated in the wooded hills of the northern Ardennes, southeast of Liege. Its popular mineral springs, known locally as pouhons, have caused the name spa to be given to all such health resorts