Merriam-Webster Collegiate Dictionary - lord

 I. noun  Etymology: Middle English loverd, ~, from Old English hlaford, from hlaf loaf + weard keeper — more at loaf, ward  Date: before 12th century  1. one having power and authority over others:  a. a ruler by hereditary right or preeminence to whom service and obedience are due  b. one of whom a fee or estate is held in feudal tenure  c. an owner of land or other real property  d. obsolete the male head of a household  e. husband  f. one that has achieved mastery or that exercises leadership or great power in some area a drug ~  2. capitalized  a. god 1  b. Jesus  3. a man of rank or high position: as  a. a feudal tenant whose right or title comes directly from the king  b. a British nobleman: as  (1) baron 2a  (2) a hereditary peer of the rank of marquess, earl, or viscount  (3) the son of a duke or a marquess or the eldest son of an earl  (4) a bishop of the Church of England  c. plural, capitalized House of Lords  4. — used as a British title: as  a. — used as part of an official title Lord Advocate Lord Mayor  b. — used informally in place of the full title for a marquess, earl, or viscount  c. — used for a baron  d. — used by courtesy before the name and surname of a younger son of a duke or a marquess  5. a person chosen to preside over a festival  II. intransitive verb  Date: 14th century to act like a ~; especially to put on airs — usually used with it ~s it over his friends