Serving is a verbal noun of serve, from Old French servir, from Latin servire ('to serve, be a slave to'), from servus ('slave'). The historical chain includes Latin servire and Latin servus. The quoted older senses, "to serve, be a slave to" and "slave", supply the semantic anchors for serving. The formation is best read as borrowed: the word serving carries its older form-history into a compact English lexical shape. In present English it is used as a noun, "a portion of food or drink for one person". Related English forms include serve, server, and service. The result is a noun and adj whose etymology preserves both the older form and the later English specialization.