The Collaborative International Dictionary of English v.0.48:

Milord \Mi*lord"\, n. [F. (also It., Sp., Russ.), fr. E. my
   lord.]
   Lit., my lord; hence (as used on the Continent), an English
   nobleman or gentleman.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

milord
    n 1: a term of address for an English lord

Moby Thesaurus II by Grady Ward, 1.0:

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