The Collaborative International Dictionary of English v.0.48:

Lordship \Lord"ship\, n.
   1. The state or condition of being a lord; hence (with his or
      your), a title applied to a lord (except an archbishop or
      duke, who is called Grace) or a judge (in Great Britain),
      etc.
      [1913 Webster]

   2. Seigniory; domain; the territory over which a lord holds
      jurisdiction; a manor.
      [1913 Webster]

            What lands and lordships for their owner know
            My quondam barber.                    --Dryden.
      [1913 Webster]

   3. Dominion; power; authority.
      [1913 Webster]

            They which are accounted to rule over the Gentiles
            exercise lordship over them.          --Mark x. 42.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Lordship
    n 1: a title used to address any British peer except a duke and
         extended to a bishop or a judge; "Your Lordship"; "His
         Lordship"
    2: the authority of a lord

Moby Thesaurus II by Grady Ward, 1.0:

142 Moby Thesaurus words for "lordship":
   acme, aedileship, archbishopric, archiepiscopacy, archiepiscopate,
   aristocracy, authority, authorization, baronetcy, barony,
   be-all and end-all, bishopric, blue ribbon, chairmanship,
   championship, chancellery, chancellorate, chancellorship, chiefery,
   chiefry, chieftaincy, chieftainry, chieftainship, command,
   consulate, consulship, control, deanery, dictatorship, dictature,
   directorship, dominion, dominium, dukedom, earldom, effectiveness,
   emirate, episcopacy, first place, first prize, governorship,
   headship, hegemony, height, hierarchy, highest, imperium,
   influence, jurisdiction, kingship, knight-errantship, knighthood,
   ladyship, land tenure, landholding, landownership, landowning,
   leadership, magistracy, magistrateship, magistrature, management,
   marquisate, masterdom, mastership, mastery, maximum, mayoralty,
   mayorship, metropolitanate, metropolitanship, most, ne plus ultra,
   new high, nobility, overlordship, ownership, palms, papacy,
   paramountcy, pashadom, pashalic, patriarchate, patriarchy,
   pontificality, pontificate, popedom, popehood, popeship,
   possessorship, power, prefectship, prefecture, premiership,
   presidency, presidentship, primacy, prime-ministership,
   prime-ministry, princedom, princeship, principality, proconsulate,
   proconsulship, proprietary, proprietorship, protectorate,
   protectorship, provostry, provostship, queenship, record,
   rectorate, rectorship, regency, regentship, rule, ruling class,
   say, seignioralty, seigniory, seneschalship, seneschalsy,
   sheikhdom, sheriffalty, sheriffcy, sheriffdom, shrievalty,
   sovereignty, supervisorship, supremacy, suzerainship, suzerainty,
   sway, top spot, tribunate, viscountcy, viscountship, viscounty,
   vizierate, viziership, zenith



Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "Lordship":
   Eminence, Grace, Her Excellency, Her Highness, Her Ladyship,
   Her Majesty, Highness, His Lordship, His Majesty, Honor,
   Imperial Highness, Imperial Majesty, Lady, Ladyship, Lord, Majesty,
   My Lady, My Lord, Reverence, Royal Highness, Royal Majesty,
   Serene Highness, Worship, Your Lordship, milady, milord