Of, relating to, or characteristic of a monarch, royalty, or (by extension) the nobility, esp. with regard to power, wealth, or dignity; (also)…

Belonging or appropriate to a king; of or relating to a king.

Of lineage, blood, etc.: connected with, originating from, a monarch or line of monarchs.

Of or belonging to a king; fit or suitable for a king; held, exercised, or issued by a king; regal.