Regal comes from Latin regalis ('royal, kingly'), from rex ('king'), from regere ('to rule, direct'), from Proto-Indo-European *h₃reǵ- ('to straighten, rule'). The historical chain includes Latin regalis, Latin rex, and Proto-Indo-European *h₃reǵ-. The quoted older senses, "royal, kingly", "king", "to rule, direct", and "to straighten, rule", supply the semantic anchors for regal. The formation is best read as borrowed: the word regal carries its older form-history into a compact English lexical shape. In present English it is used as a adj, "of, resembling, or fit for a monarch; majestic". English derivatives include regally and regality; related English forms include regalia, reign, royal, and rex. The result is a adj whose etymology preserves both the older form and the later English specialization.