The Collaborative International Dictionary of English v.0.48:

Royalty \Roy"al*ty\, n.; pl. Royalties. [OF. roialt['e],
   royault['e], F. royaut['e]. See Royal, and cf. Regality.]
   1. The state of being royal; the condition or quality of a
      royal person; kingship; kingly office; sovereignty.
      [1913 Webster]

            Royalty by birth was the sweetest way of majesty.
                                                  --Holyday.
      [1913 Webster]

   2. The person of a king or sovereign; majesty; as, in the
      presence of royalty.
      [1913 Webster]

            For thus his royalty doth speak.      --Shak.
      [1913 Webster]

   3. An emblem of royalty; -- usually in the plural, meaning
      regalia. [Obs.]
      [1913 Webster]

            Wherefore do I assume
            These royalties, and not refuse to reign? --Milton.
      [1913 Webster]

   4. Kingliness; spirit of regal authority.
      [1913 Webster]

            In his royalty of nature
            Reigns that which would be fear'd.    --Shak.
      [1913 Webster]

   5. Domain; province; sphere. --Sir W. Scott.
      [1913 Webster]

   6. That which is due to a sovereign, as a seigniorage on gold
      and silver coined at the mint, metals taken from mines,
      etc.; the tax exacted in lieu of such share; imperiality.
      [1913 Webster]

   7. A share of the product or profit (as of a mine, forest,
      etc.), reserved by the owner for permitting another to use
      the property.
      [1913 Webster]

   8. Hence (Com.), a duty paid by a manufacturer to the owner
      of a patent or a copyright at a certain rate for each
      article manufactured; or, a percentage paid to the owner
      of an article by one who hires the use of it.
      [1913 Webster]

WordNet (r) 3.0 (2006):

royalty
    n 1: payment to the holder of a patent or copyright or resource
         for the right to use their property; "he received royalties
         on his book"
    2: royal persons collectively; "the wedding was attended by
       royalty" [syn: royalty, royal family, royal line,
       royal house]

Moby Thesaurus II by Grady Ward, 1.0:

128 Moby Thesaurus words for "royalty":
   FFVs, ancestry, ancienne noblesse, anointed king, aristocracy,
   aristocraticalness, avails, baronage, baronetage, birth, blood,
   blue blood, box office, caliphate, chief, chieftain, chivalry,
   commission, commissions, compensation, credit, credits,
   crowned head, cut, czardom, disposable income, distinction,
   dividend, dividends, dynast, earned income, earnings, elect, elite,
   emperor, emperorship, empery, empire, gains, gate, gate receipts,
   genteelness, gentility, get, grand duke, gross, gross income,
   gross receipts, haut monde, high chief, high life, high society,
   honorable descent, imperator, imperialism, income, intake,
   kaiserdom, kaisership, king, king-emperor, kinghood, kinglet,
   kingship, knightage, lord paramount, majesty, make, monarch, net,
   net income, net receipts, nobility, noble birth, nobleness,
   noblesse, noblesse de robe, old nobility, output, overlord,
   paramount, payment, peerage, percentage, petty king, potentate,
   prince, prince consort, proceeds, produce, profits, quality,
   queenhood, queenship, rajaship, rake-off, rank, receipt, receipts,
   receivables, regnancy, returns, revenue, royal, royal personage,
   royalties, ruler, share, sovereign, sovereignty, sultanate,
   sultanship, suzerain, take, take-in, takings, tetrarch,
   the Four Hundred, the classes, the crown, the throne,
   unearned income, upper classes, upper crust, upper ten,
   upper ten thousand, uppercut, yield